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Full text of "United States Navy Medical News Letter Vol. 43 No. 3, 7 February 1964"

FEB J 5 1964 



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UNITED STATES NAVY I 

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Vol. 43 



Friday, 7 February 1964 



No. 3 



TABLE OF CONTENTS 



MEDICAL ABSTRACTS 

Tropical Medicine Symposimn: 
Current Worldwide Importance 

of Arboviruses 3 

Laboratory Methods for Diagnosis 
of Parasitic Infection ........ 6 

Clonorchiasis 8 

Infection Control in Tropical 

Surgery 9 

Fainting H 

SUBMARINE MEDICINE 



Basic Physiology in Scuba and 
Skin Diving 



15 



FROM THE NOTE BOOK 



First Cruise Reenlistment . . 19 

Naval Historical Foundation 20 

Navy Nurses Program in 

Anesthesia 20 

NC Senior Officer Assignments ... 21 
Radioactivity - New Publication ... 21 

DENTAL SECTION 

The Physician, the Patient, and 

Statistics 22 



DENTAL SECTION (Cont'd) 

Pathogenesis of Bacterial 

Endocarditis 23 

Dental Sepsis and Lung 

Infection 23 

Research on Initiation of 

Periodontal Disease 24 

Personnel and Professional 

Notes 25 

OCCUPATIONAL MEDICINE 

Chemical Health Hazards and 

Their Control 27 

Detection of Nonorganic Hearing 
Loss 29 

Laser -Medical and industrial 

Hygiene Controls 33 

RESERVE SECTION 

Meeting of American. Mosquito 

Control Association 38 

Attention: Opportunities for 
Reserve Nurse Corps Officers 
on Inactive Duty 38 

Sectional Meetings of ACS 38 

Navy Ensign 1915 Medical 

Program 39 



mmGm general hospital 

"EDICAL LIBRARY 
r'ROFERTV' OF U, S. ARMY 



United States Navy 
MEDICAL NEWS LETTER 



Vol. 43 Friday, 7 February 1964 No. 3 

Rear Admiral Edward C. Kenney MC USN 
Surgeon General 
Rear Adnnlral A.5. Chrisman MC USN 
Deputy Surgeon General 

Captain M. W. Arnold MC USN (Ret), Editor 

Contributing Editors 

Aviation Medicine Captain C, E. Wilbur MC USN 

Dental Section Captain C. A. Ostrom DC USN 

Occupational Medicine CDR N. E, Rosenwinkel MC USN 

Preventive Medicine Captain J. W. Millar MC USN 

Radiation Medicine CDR J. H. Schulte MC USN 

Reserve Section Captain K, W. Schenck MC USNR 

Submarine Medicine CDR J. H. Schulte MC USN 



Policy 

The U.S. Navy Medical News Letter is basically an official Medical Depart- 
ment publication inviting the attention of officers of the Medical Department 
of th« Regular Navy and Naval Reserve to timely up-to-date items of official 
and professional Interest relative to miedicine, dentistry, and allied sciences. 
Th« amount of information used is only that necessary to inform adequately 
officers of the Medical Department of the existence and source of such infor- 
mation. The items used are neither intended to be, nor are they, susceptible 
to uae by any officer as a substitute for any item or article in its original 
form. All readers of the News Letter are urged to obtain the original of those 
items of particular interest to the individual. 

Change of Address 

Please forward changes of address for the News Letter to: Commanding Officer, 
U. S. Naval Medical School, National Naval Medical Center, Bethesda, Maryland 
ZOOM, giving full name, rank, corps, and old and new addresses. 



The issuance of this publication approved by the Secretary of the Navy on 
28 June 1961. 



Medical News Letter, Vol. 43, No. 3 



Carrent Worldwide Importance of Arboviruses ■'' 

William C. Reeves PhD, Professor of Epidemiology, University of 
California School of Public Health 

Arboviruses constitute an extremely large group of infectious agents. All have 
the characteristic of infecting vertebrate hosts in which they may or may 
not produce clinical disease. When they infect these hosts they must produce 
a viremia, else the hosts cannot serve as sources of vector infection. All of 
these viruses are biologically transmitted by a blood-sucking arthropod in 
which they multiply and cause infection. One hundred fifty viruses are now 
known to be carried by ticks, mites, or mosquitoes; one hundred twenty-eight 
have been described in detail. 

Prior to 1930, only five of the classical viruses were known, includ- 
ing the yellow fever, dengue, and Japanese B encephalitis viruses. During 
the following decade, eight more were discovered, including those causing 
Western equine and St. Louis encephalitis. Since then, a fantastic increase 
has accrued as a result of increased research effort in the tropics. 

Antigenetically, arboviruses are a complex group separable into a 
number of divisions by serologic means. It is particularly important to 
recognize Group A viruses, 'such as Western and Eastern equine, and Group B 
viruses, such as yellow fever and dengue. 

Arboviruses have a broad geographic distribution; in all of the land 
masses in tropical or temperate zones, they are represented. North America, 
Europe, and Australia, being in the temperate zone, have fewer species than 
tropical areas where, as with plants and animals, more species develop. A 
few viruses are found on as nnany as four continents; man or his domestic 
animals seem capable of distributing these viruses nnost rapidly and effectively. 
Viruses found on only one or two continents have a less efficient means 
of spread to man and domestic animals; birds and rodents serve as primary 
hosts. 

Forty-nine of these viruses have been isolated from arthropods, but 
as yet undemonstrated is their relationship to vertebrate hosts. Thirty 
more related viruses may fall into this group. Ninety-eight of these agents 
have definitely been shown to be tied in with an arthropod vector, and only 
thirty have not, as yet, been associated with a vector. Seventy -nine have 
been isolated in vertebrates; forty-nine others have not been isolated from 
a vertebrate host, but there is serologic evidence to indicate that they do 

* This is the eleventh paper from the Tropical Medicine Symposium, USNH 
Oakland, Calif. , March 14 and 15, 1963. The preceding papers were 
published in the Medical News Letters of 15 November and 6 December 
1963, and 3 January 1964. Edited by Captain Arthur J. Draper MC USN; 
authorized by the C O of the Hospital, Rear Admiral Cecil L. Andrews 
MC USN. 



4 Medical News Letter, Vol. 43, No. 3 

affect vertebrates. Forty-eight of these viruses have been isolated froin 
human beings in whom clinical disease of some type was present. In addition, 
twenty-eight have been shown by serologic means to stimulate the production 
of antibodies in man. Still others under study have either experimentally or 
accidentally infected man under laboratory conditions. 

In man, arboviruses produce a broad range of clinical syndromes. 
Some are generalized, fever, malaise, headache, and pain; these include 
Mayaro and O'nyong nyong infections of the tropics, relatively mild disorders, 
as well as dengue types 1 and 2. The newer dengue types 3 and 4 cause a 
hemorrhagic type of disease. Classical encephalitides result from infection 
with Western equine or Japanese B viruses. Some types affect certain organs, 
such as yellow fever or Rift Valley fever. A number of other diseases pro- 
duced are not yet really characterized. To stress the worldwide importance 
of arboviruses, a world tour will now be conducted! Epidemics which have 
occurred within the past two years will be the primary concern. 

In the St. Petersburg-Tampa area of the United States during 1962, 
there was an extensive epidemic of St. Louis encephalitis. Over five hundred 
people, mostly elderly, became ill; 158 cases were confirmed by laboratory 
tests. Seventeen deaths occurred. Fortunately, the epidemic halted before 
November 1962 when thousands of troops were ordered into the area in asso- 
ciation with the Cuban crisis. 

An outbreak of Eastern equine encephalitis is going on in Jamaica at 
this time (March 1963). There have been 11 human cases and 9 deaths. At 
least 70 horses have died. Very likely Cuba is having a similar outbreak. 
It is rumored that dengue is also epidemic in Cuba, 

Venezuelan equine encephalitis has been reported extensively for 
several years in Panama. This has not been primarily a horse disease; over 
350 human cases have been observed. The disease is characterized by a 
severe febrile reaction with a fair mortality rate. Protection of troops in the 
area has been a naajor concern. Also, in Panama, an outbreak of Eastern 
equine encephalitis has been reported, with no human cases thus far. 

An interesting and troublesome problem has presented itself in Colom- 
bia. At first report, thousands of cases of a disease of unknown cause were 
observed. Investigation revealed the disease to be Venezuelan equine enceph- 
alitis. Between six and seven thousand people have been affected, over one 
hundred of whom died. Concomitantly, an extensive horse outbreak took 
place with many deaths. In another area of Colombia, a similar outbreak 
occurred from which a new unidentified virus was isolated, both from man 
and mosquitoes. Yellow fever, too, is rumored to have been found up river 
from Barranquilla. A type of hemorrhagic fever has been observed in Bolivia, 
involving over one hundred cases and associated with a mortality rate of 40% 
to 50%. The disease is most likely a northward extension of the epidemic 
hemorrhagic fever, mite-borne, of Argentina, which in that country has lately 
produced two or three thousand cases with a 25% mortality. 

O'nyong nyong, meaning "something new, " is the name given by the 
natives of Uganda in the interior of Africa to what is, indeed, a new disease 



Medical News Letter, Vol. 43, No. 3 5 

caused by a new virus. It has caused over two million cases of mild febrile 
illness with a low mortality rate. The virus is the first of its type to have 
as its vector an Anopheles mosquito. There is no natural barrier to prevent 
the spread of this disease into other areas of Africa. In Ethiopia, the largest 
yellow fever epidemic of modern tim^es has been raging. In the absence of a 
census or medical service, the incidence or mortality rate of this epidemic 
will never be known. 

From South Africa, via Egypt and Turkey, African horse sickness 
has spread into India and Pakistan. Killing more than fifty thousand horses, 
the disease threatens the agricultural economy of the area. The Indian cav- 
alry — an important part of the armed forces — has been threatened with ex- 
tinction. An effective vaccine has been developed. 

In the Mysore State in central India, a new disease was recognized in 
1957. Initially thought to be yellow fever, never before described in Asia, 
the disease turned out to be tick-borne Russian spring-summer encephalitis, 
Locally, it is known as Kyasanur, "forest disease. " It causes a highly fatal 
disease in monkeys; hundreds of human cases, too, have shown a high mor- 
tality rate. Recently, it has been discovered to be extending; an associated 
virus occurs in Malaya. 

Finally, there are the hennorrhagic fevers which are discussed else- 
where in this symposium. They have occurred in the Philippines, Malaya, 
and Bangkok. During the past year, four thousand cases have been reported 
from Bangkok alone, probably half those which actually occurred. Mortality 
rate was 5%. 

Clearly, the arthropod-borne viruses are capable of producing exten- 
sive epidemics. Besides the diseases mentioned, dengue fever and Japanese 
B encephalitis pose major problems throughout the Asian nna inland and the 
adjacent island complexes. Tick-borne viruses are scattered throughout 
Europe and Russia, and mosquito-borne viruses are well known in North and 
South America. 

The infection cycle of these viruses is very complex. Basically, they 
all have a vertebrate host; mosquitoes or other arthropods serve as vectors 
for their transmission to other vertebrate hosts. Some of the agents can go 
directly from one vertebrate host to another by way of milk, feces, or other 
such avenues. The problem is to discover what portion of this type of infec- 
tion chain is essential to maintain the virus in its natural cycle so that there 
may be a possibility of interrupting it. Then, too, a means may be devised 
to protect man from accidental tangential exposure in instances in which man 
is an accidental host not essential to the perpetuation of the virus. 

Prevention of human illness from this group of viruses is really quite 
limited at present. Knocking out the mosquito vector would interrupt the 
basic infection cycle and prevent perpetuation of virus transmission for some 
representatives, but this has not been done successfully in some areas, even 
inthe case of Aedes aegypti , a domestic mosquito. Eradication of even this one 
insect is an extremely expensive process. Application of insecticides to vast 
jungle areas in an effort to control, say, sylvatic yellow fever, is manifestly 
impossible. In combat operations, control measures are directed toward 



6 Medical News Letter, Vol. 43, No. 3 

mosquito repellents, protective clothing, and adequate housing. Strict disci- 
pline is needed to enforce such measures. Vaccination, save in the case of 
yellow fever, is largely ineffective. Extensive research is being conducted 
to develop vaccines against dengue viruses and Japanese B as well as other 
encephalitis viruses. Especially desirable would be a good living attenuated 
agent which would confer protection for many years. 

*«Ju «J> «^ ^t^ Ji^ 
f^ irfi a^ irp r^ 

Laboratory Methods for Diagnosis 
of Parasitic Infection 

Quentin M. Geiman PhD, Professor of Preventive Medicine, Stanford 
University School of Medicine. 

This presentation reviews a parade of parasites and takes up some problems 
in the diagnosis of parasitic infection, A few general remarks are in order. 
First, the physician has the responsibility of supervising laboratory tech- 
nicians who make the diagnosis. Also, he should make sure that specimens 
are properly collected and delivered to the laboratory. Findings upon repeated 
exanainations and interpretation of results are as good as the laboratory per- 
sonnel who perform them. Finally, another point to be emphasized is the 
necessity of follow-up after diagnosis and treatment. Parasites, especially 
intestinal parasites, may multiply and return. Examination of specimens 
taken 3 to 4 weeks after cessation of treatment is necessary to exclude such 
a recurrence. 

The parade of parasites consisted of numbered slides and parenthetical 
remarks by Dr. Geiman. Stool specimens are necessary to detect amebiasis, 
especially in patients in the tropics upon whom surgical procedures are con- 
templated. Giardia infection may produce extensive diarrhea but is never 
bloody. Balantidial infection may also be detected in the stool. Coccidiosis 
is rare. Trichomonas vaginalis may be recovered from cases with vaginitis; 
the infection may also occur in the male, in which event, examination of the 
prostatic fluid will reveal the organism. Also, there are the intestinal hel- 
minths, particularly Fasciolopsis and the tapeworms. Taenia saginata is not 
uncommon in California since many people like rare steak, but T. solium 
does not occur there. The broad of fish tapeworm can occur, although it is 
of lesser importance. The pinworm is universal, connmonly diagnosed by the 
use of the NIH swab. Once a child brings home the infection, the whole family 
usually get it; the family — not just the first child — must be treated. Strongy - 
loides infection can produce an extensive diarrhea; it occurs in California and 
is common in the tropics. Trichinosis and visceral larva migrans lead to the 
tissue helminths. Visceral larva migrans — much studied of late — represents 
infection by dog or cat nematodes which are responsible for a certain percent- 
age of tropical eosinophilia. Diagnosis is usually difficult. Cystocercosis 
results from tissue infestation with larvae of the intestinal parasite Taenia 



Medical News Letter, Vol. 43, No. 3 7 

solium , the pork tapeworm. Filariasis has been discussed at length else- 
where in this symposium. 

Malaria results from a blood parasite. Dr. Thompson discussed the 
preparation of thin and thick smears for detection of these organisms. Thick 
smears (which must be properly prepared on the slide or it will appear as 
though the patient had had a hemorrhage) are useful for diagnosing trypano- 
somiasis, relapsing fever, and even toxoplasmosis. 

Leishmaniasis may be diagnosed from study of the blood, biopsy of 
the spleen, blood culture, marrow culture, and from cutaneous lesions. 
Cutaneous leishmaniasis may cause scarring of the nose and face. In South 
America, mucocutaneous infection may destroy the nasal septum. A sero- 
logic test commonly used in Central America, the Montenegro reaction, is 
95% to 98% valid in determining cutaneous leishmaniasis, but ineffective for 
the purpose in visceral forms. The differential diagnosis of the skin lesion 
may be difficult. Occurrence in an endemic area will alert the examiner, 
but the appearance of the lesion resem,bles spirochetal infection, cutaneous 
diphtheria, or fungus infection, especially if it does not have the indurated 
margin which usually characterizes leishmaniasis. Yaws, syphilis, or tropical 
ulcer nnust also be considered. For diagnosis, material must be taken, not 
from the base, but from the margin of the ulcer where parasites are usually 
found. Skin lesions are for the most part on the exposed parts of the body 
where biting sandflies take their blood meal. 

Toxoplasmosis, extensively studied recently, is a sort of parasite in 
itself. Toxoplasma gondii . The organisms appear, beside leukocytes, as 
small crescentic shapes. At times, they appear in clusters as in sections of 
the human heart. One test for the presence of toxoplasmosis is the Sabin- 
Feldman dye test; animal inoculation is also successful. 

In the more bizarre types of blood-stream infections, such as sleeping 
sickness, blood studies, lym^ph node aspiration, and spinal tap are helpful 
approaches to diagnosis. Chagas' disease (American trypanosomiasis), 
common throughout Central and South America, shows a question mark shape 
in thin or thick blood films. Tissue stages of the disease closely resemble 
leishmaniasis. Another method of study is. to feed noninfected triatomid bugs, 
the vectors, on the patient and see if trypanosomes grow out. 

Schistosomiasis is a major medical problem throughout the world. 
Some 2500 cases occurred during the invasion of Leyte Gulf during World 
War II. A blood fluke is the responsible organism. Eggs of the parasite 
should be sought in the stool or urine of the affected patient. Serologic methods 
of diagnosis are being tried; work is being done with fluorescent antibodies. 
Field tests are being carried out in Africa with an antigen against Schisto- 
soma mansoni . 

Among liver flukes are included clonorchiasis and hydatid disease 
which may also involve the lung. Enormous numbers of daughter cysts may 
occur in a liver containing a parent cyst. Material from daughter cysts may 
show the scolices and booklets of the scolices. A serologic test for hydatid 
disease gave a definite positive reaction in one case at Stanford. 



8 Medical News Letter, Vol. 43, No. 3 



Clonorchiasis 

Walter G. Strauss MD, Assistant Clinical Professor of Medicine, 
University of California Medical Center. 

Clonorchiasis, infection with the Chinese liver fluke, endemic in large areas 
of the Orient, is transmitted only in that area. It is found, of course, in 
patients outside the endemic; viz. , the San Francisco Bay Area where it is 
the most common tropical disease. In San Francisco in 1901, it was first 
discovered in the course of autopsy studies on Chinese who had died of plague. 
For a time thereafter, health regulations excluded from the United States 
those Chinese who showed clonorchis in the stool. No reservoirs or animal 
hosts for the organism have been demonstrated in the United States. 

Clonorchis sinensis is a platyhelminth, flatworm, 15 mm long and 
3 mm wide. Anteriorly, there is a small sucker which opens shortly into 
a pharyngeal pouch, esophagus, then fiburcates into a paired intestine which 
ends blindly. The animal regurgitates the products of digestion out of the 
oral sucker. A second sucker is directly connected with the genitalia. The 
branched genital structures give the animal its name — "clonorchis" means 
"convulated testes, " 

The adult organism lives in the bile ducts of man or the reservoir 
hosts; infection may consist of a very few or a great number of organisms. 
The eggs are passed through the bile ducts, mingle with the intestinal contents, 
and fall into fresh water with the stool. Intermediate stages develop in snails 
and then in fish belonging to the carp family. Man becomes infected by eating 
raw carp. This cycle reaches com^pletion only in China, Japan, Korea, and 
Formosa. 

During the late 1930 's, many refugees from Nazi tyranny fled to 
Shanghai. Accustomed in Germany to eating Bismarck herring, these people 
relished the Chinese fresh water carp which were heavily contaminated with 
clonorchis. Immigration of about 1200 German refugees from Shanghai into 
San Francisco has afforded the author an opportunity to pursue comparative 
studies of clonorchiasis as manifested in this group and in Chinese in San 
Francisco. About 40% of the first group have been found by stool examination 
to be infected; the author estimates that about 16% of Chinese individuals out 
of the 36, 000 living in the Bay Area are infected, A considerable number of 
European Russians, and a few Koreans in the area are also infected. The 
Japanese, of whom some 7000 live in the Bay Area, are not infected, nor have 
members of the U. S. Armed Forces been found to be infected. 

With respect to symptomatology of the disease, the medical literature 
is confusing. Meyer, in Germany, for instance, found it harmless among 
Chinese merchant seamen in Hamburg. Berkowitz, by contrast, described 
in Americans a disease with high mortality. Clinical observations made by 
other writers have varied widely. 

The author subjected the clinical data amassed from 105 cases to me- 
ticulous analysis. Forty-eight Caucasians seemed to have a high incidence of 



Medical News Letter, Vol. 43, No. 3 9 

abdominal complaints as contrasted with the rarely symptomatic Orientals. 
Weight of infection as judged by the number of eggs per gram of stool was not 
an explanation. Statistical analysis showed no difference in occurrence of 
symptoms in infected Caucasians as compared with uninfected Caucasians, nor 
was there a difference between Orientals with and those without Clonorchis. 
Symptoms ascribed to clonorchiasis in the past, then, appear to be more a 
function of the ethnic group infected than of the presence of infection. The 
author concludes that ordinarily there is no symptom -complex or group of 
findings which can be called "clonorchiasis. " 

^ ^ ^ :{: ^ :}: 

Infection Control in Tropical Surgery 



Charles B. Beal MD, Instructor in Preventive Medicine, Stanford 
University School of Medicine. 

Hazards in diagnosis and management confronting the surgeon, and hazards 
of infection or cross -infection facing the patient in tropical areas form the 
substance of this presentation. 

Amebiasis, ascariasis, and malaria may be considered three tropical 
diseases which present difficult problems in diagnosis and management. The 
protean manifestations of amebiasis may involve the bowel, liver, pulmonary 
systenn, genital tract, central nervous system, and the skin. Aineboma may 
mimic carcinoma of the large bowel. Amebic infection of the cervix has been 
mistaken for advanced malignancy. An infection of the cecum commonly 
presents like appendicitis. Enlarged tender liver, without jaundice and with 
very little derangement of liver function tests, may represent amebic hepatitis 
rather than viral hepatitis. If liver abscess develops, the first requisite for 
diagnosis is the knowledge that it might be amebic in origin. Since tropho- 
zoites — more often than not — do not appear in the stool, a trial of emetine or 
chloroquine, or judicious aspiration may clarify the problem. 

Ascariasis may present a difficult problem in diagnosis, especially in 
terms of obstruction, and particularly in children. A palpable mass suggests 
intussusception which, indeed, may accompany ascariasis of the bowel. A 
bolus of ascarids in the ileum has a doughy or crepitant feel which is almost 
pathognomonic. A history of the passing of ascarid in the stool, or the demon- 
stration of ova on a fingercot specimen aid in diagnosis. X-ray examination, 
especially with barium, may show a "wound-up ball of string" picture. Man- 
agement is best carried out by intestinal intubation for decompression; piper- 
azine (Antepar) through the tube should be administered. Abdominal massage 
is dangerous. Laparotonay, necessary at times, gives an opportunity to milk 
the worms through the ileum to the cecum or to remove them one by one from 
the opened bowel. Closure must be accomplished in healthy tissue or any 
worms left will migrate into the peritoneal cavity or right out through the sur- 
gical wound ! 



fllO Medical News Letter, Vol. 43, No. 3 

Since malaria tends to relapse after stress, operation, childbirth or 
injury, it is most often a complication bat may pose a diagnostic problem in 
the postoperative or postpartuna state. Falciparum , or malignant tertian 
malaria, may cause acute abdominal pain. 

Infection acquired by the patient in the hospital — everywhere a 
problem — in the tropics is an extrennely formidable adversary of the surgeon. 
First, the skin of the patient himself may be contaminated with staphylococcus. 
In a hospital in Central America, for example, a high incidence of breast 
abscess in mothers was found attributable to the fact that 99% of infants were 
colonized by the third hospital day with resistant staphylococcus. Phis obex 
(cleansing) for the babies appeared successful in controlling the problem. 
Also, wounds that contain a great deal of necrotic tissue and hematomata, 
especially if contaminated, are likely to become infected. Where filariasis 
is endemic, 50% of surgical wounds chronically drain. In the presence of 
elephantiasis, the skin is very hard to clean and hemostasis is difficult. 
Surgical drains result in a 100% infection rate. Organisms other than staphy- 
lococcus, of course, may cause wound infection, viz. , streptococci, diphth - 
eriae and Clostridia. 

In the attempt to meet the problem of infection, the design of the hos- 
pital itself must be considered. The classical European style colonial building, 
by contrast with temperate zone hospitals with central quarters and nursing 
stations, has quarters which open to the outside. Advantages of this design 
are that patients get any available breeze and the air blowing in is confined to 
the individual room rather than blowing throughout a large central ward. The 
chief disadvantage is a loss of nursing efficiency. Vigilance must be exer- 
cised to see that nursing technics do not become careless. 

Other problems, more pressing in tropical areas than elsewhere, are 
fly control, blood transfusion, and anesthesia. Many agents produce contagion 
in blood transfusion. Although malaria and syphilis are no longer major con- 
siderations, viral hepatitis is a grave possibility. In Nigeria, for example, 
5% of blood transfusions produce hepatitis; the mortality rate in patients over 
age 40 from homologous serunn hepatitis is 22%. 

In the struggle against flies and infection, the author has devised a 
method of isolating the operative area by means of a plastic bag attached to 
the patient with sterile glue. The bag, inflated with filtered sterile air, con- 
tains adjustable armlets through which the surgeon thrusts his arm; he n:iay 
work with entirely satisfactory visibility with surgical instruments which 
have been placed in the sterilized area within the bag. Examples of the use 
of this procedure in repair of inguinal hernia, lobectomy for pulmonary 
tuberculosis, several orthopedic operations, and one mastectomy were shown 
on slides. A similar technic is helpful in protecting the wound during the 
postoperative period. 

ijC ifi i^ ylp. •rji rfi 



Medical News Letter, Vol. 43, No. 3 H 



FAINTING * 

Juergen E. Thomas MD and E. Douglas Rooke MD, Section of Neurology, 
Mayo Clinic, Rochester, Minn. Proceedings of the Staff Meetings of The 
Mayo Clinic 38(19), September 11, 1963. 

A list of the main conditions with clinical features that can be confused with 
syncope might include epilepsy, vertigo, hyperventilation, hysteria, and 
migraine. Episodic cerebrovascular Insufficiency may sometimes need to be 
considered. This condition has already been discussed in a previous section. 
Narcolepsy, cataplexy, hypoglycemia, and tetany are occasionally mentioned 
in the differential diagnosis of syncope, but in almost every instance a care- 
ful history will reveal obvious points of distinction. 

Epilepsy . In evaluation of "spells" the most frequent uncertainty is 
the distinction between syncopal and convulsive mechanisms; indeed, there 
are times when the history alone will permit no clear choice, especially when 
only a few episodes have occurred. For the most part, however, the distinc- 
tion can be made with the following points in mind: 

Speed of Onset . Most syncopal attacks feature a brief period of warn- 
ing before consciousness is lost — a fading or graying of vision, squeamish- 
ness in the stomach, cold perspiration, and weakness in the legs. One 
must distinguish these complaints from the aura of a convulsive state, and 
one of the most obvious differences is the favorable influence of recumbency 
in syncope. 

Many convulsive episodes begin abruptly without warning of any kind. 
Even when there is an aura, it is usually a consistently repetitive chain 
of events more often sensory than motor, and with the possible exception 
of the rising epigastric aura of temporal lobe epilepsy, the premonitory 
experiences have little in common with the symptoms of syncope. 

An abrupt onset without warning of any kind does not entirely exclude 
the diagnosis of syncope since cardiac conditions (for example, Morgagni- 
Adams-Stokes syndrome) can manifest themselves in just this way. The 
great majority of such sudden episodes, however, prove to be convulsive 
in nature. 

Consistency of Pattern . This is a characteristic of epilepsy but not of 
syncope. Once the chain of events is initiated in epilepsy, it tends to run 
its identical course on each occasion, and the duration of each separate 
episode is also quite consistent. A syncopal spell, on the other hand, may 
be modified by prompt remedial measures (especially recumbency), and 
different episodes may vary greatly in length depending on how rapidly 
these measures are taken or how quickly an underlying cardiac dysrhythmia 
improves. 



* Concluded from the Medical News Letter, Vol. 43, No. 2, 24 January 1964. 



12 Medical News Letter, Vol. 43, No. 3 

P ostural Influence . Except for cardiac syncope, a rare disturbance 
that can occur with the patient in any position, syncopal episodes occur 
with the patient upright, usually standing .but sometimes sitting. A clinical 
history in which spells have never occurred during recumbency or sleep 
would favor the diagnosis of syncope over that of epilepsy. 

Motor Phenomena. Convulsive movements are not confined to the epi- 
leptic state, and after the loss of consciousness in severe syncope, spasms, 
twitching, and mild convulsive movements can be seen. 

Skin Changes . These may also be helpful since syncope is usually 
featured by marked pallor, often with cold perspiration. An occasional 
patient in an akinetic epileptic state may also appear pale, but for the most 
part, flushing or cyanosis with warm perspiration during a spell is much 
more characteristic of the convulsive state and is not seen in syncope. 

Sphincter Incontinence and Tongue Biting . These are certainly "con- 
vulsive " features, but urinary incontinence has been seen in particularly 
severe syncope, and it is possible for a patient to faint so abruptly that the 
tongue can be injured in his fall. 

Recovery . Recovery from a faint is usually rapid with prompt orienta- 
tion, rarely any headache, and no amnesia. The spell is vividly recalled, 
sometimes even including audible events that occurred after the patient 
appeared to be unconscious. In syncope, physical weakness and fatigue 
outlast the disturbance in consciousness and the patient prefers to remain 
inactive after regaining consciousness. 

Following a convulsive episode, on the other hand, varying degrees of 
bewilderment are frequently seen and headache is common. The patient is 
often able to be up and moving about for several minutes before his mind 
clears completely and he may then prefer to sleep for an hour or so. 

In spite of all these distinctive features, spells will still be described 
about which a definite decision cannot be made. In these instances, the 
electroencephalogram may sometimes be helpful. However, a normal 
interval record does not exclude epilepsy any more than a moderate 
dysrhythmia in the brain waves excludes the possibility of a syncopal 
mechanism. 

Vertigo . Vertigo will seldom be confused with syncope if the patient 
can be induced to describe exactly what he experiences. In this condition, 
there is a sense of movement either in the environment or of the patient 
himself. Falling may be abrupt and violent, but consciousness is not lost. 
Nausea is frequent and the associated pallor and cold sweat may sometimes 
suggest fainting to an unwary observer. The increased distress with head 
movement is quite characteristic of vertigo and seldom seen in syncope. 

Hyperventilation . This phenomenon may complicate several different 
conditions including syncope itself. It is usually a manifestation of an 
emotional disturbance and when repetitively recurring can pose a diagnostic 
problem. The sensation of needing more air, with resultant deep and rapid 
breathing, may not be described spontaneously by the patient and needs 



Medical News Letter, Vol. 43, No. 3 13 

specific inquiry by the examiner. Symptoms of faintness, lightheadedness, 
paresthesias of the fingers, lips, and toes bilaterally should stimulate such 
an inquiry. Hyperventilation spells may constitute the whole problem in them- 
selves, but they may also be secondary reactions to a true syncopal attack 
and these two conditions are not mutually exclusive. 

Hysteria . This condition can usually be distinguished from syncope 
by the calm detachment with which the patient describes her symptoms, the 
vagueness of description, the absence of pallor and sweating as described by 
others, and the almost invariable presence of an audience. These episodes 
are not dependent on the upright position and do not respond so promptly to 
recumbency. Hyperventilation may also be part of the picture. The patient 
is likely to be either a naive unsophisticated young person or an older one in 
whom a previous conversion tendency can be established. Hysteria is not 
entirely confined to females, but occurs much more frequently in them than 
in males. One should always be skeptical about "hysteria" that appears un- 
heralded in middle age or later. It may prove to be something else. 

Migraine . Attacks of migraine ordinarily have no syncopal features, 
but Bickerstaff (25, 26) and Selby and Lance (27) have drawn attention to a 
rare situation in which the basilar arterial system may be involved in addition 
to or instead of the more commonly affected carotid system. In these patients, 
usually adolescent girls, the premonitory aura of a migrainous episode term- 
inates in deep unconsciousness of several minutes' duration, followed by 
severe headache typically occipital in location. 

Conclusion 

Among the disorders of consciousness, syncope is probably the least alarm- 
ing and the most benign of all. Its manifestations are characteristically pro- 
tean and tend to vary in intensity, duration, and character from one attack to 
the other. With a few exceptions, autonomic features such as pallor, nausea, 
and perspiration are prominent and may precede and outlast the spell for 
some time. The faint occurs almost always while the patient is upright, its 
onset is probably never as instantaneous and the level of consciousness is not 
as profoundly depressed as in an epileptic seizure. Minor convulsive twitch- 
ing of the face and extremities can occur, but usually lasts only a matter of 
seconds and does not pursue the sequence of a grand mal attack. Oftentimes, 
the syncopal spell can be alleviated by quick assumption of the recumbent 

position. 

Vasodepressor syncope outranks all others in frequency of occurrence. 
In contrast, syncope caused by orthostatic hypotension, primary and reflex 
cardiac disorders, coughing, and cerebrovascular disease is rare. None of 
the clinical manifestations comprising the syncopal syndrome is sufficiently 
distinctive to provide conclusive evidence of the underlying cause. However, 
in many instances, valuable information can be gained from a careful analy- 
sis of such factors as age of the patient, the position of the body at the time 



14 Medical News Letter, Vol. 43, No. 3 

of the faint, the duration as well as the inanner of onset of and recovery from 
the spell, and the associated symptoms and signs. 

Syncope occurring in the young person is predominantly of vasodepres- 
sor type. Rare other causes at this age are congenital cardiac anomalies, 
valvular heart disease and paroxysmal tachycardia. In later adult life, vaso- 
depressor syncope occurs less frequently and organic conditions, such as 
intrinsic heart disease, orthostatic hypotension, carotid sinus hypersensitivity, 
and cerebrovascular disorders, are more common. 

Presyncopal symptoms are often pronounced and prolonged in the 
ordinary vasodepressor faint, while sudden loss of consciousness without 
warning may occur in primary or reflex cardiac asystole and in severe ortho- 
static hypotension. The latter is also the likely offender when syncope follows 
assumption of the upright position. The occasional faint affecting the recum- 
bent patient is probably due to prolonged cardiac asystole. Loss of conscious- 
ness related to exertional activity suggests as the cause aortic stenosis, 
coronary heart disease, primary pulmonary hypertension, orthostatic hypo- 
tension, congenital cardiac anomalies, or the aortic arch syndromte. Brady- 
dardia of less than 40 beats per minute points to a complete heart block; and 
tachycardia of more than 150 beats per minute implies an ectopic cardiac 
rhythm. 

Since only rarely can the physician witness a spontaneous attack, 
recognition of the syncopal nature of the spell and its differential diagnostic 
separation from other conditions often depends entirely on the history. In 
final analysis, it should be remembered that the total picture of the attack is 
often more important than the presence or absence of any isolated symptom. 

If general physical and neurologic examinations fail to reveal the cause 
of the syncope, attempts should be made to reproduce an attack by provocative 
maneuvers, such as carotid sinus stimulation, postural changes of the body, 
and voluntary hyperventilation. However, positive results of such tests can 
be considered diagnostic only when they produce symptoms identical to those 
experienced in the spontaneous attack. Abnormalities in the electrocardio- 
gram will raise the physician's index of suspicion, but do not necessarily 
establish a diagnosis of cardiac syncope. Similarly, a normal electrocardio- 
gram does not exclude a cardiac etiology. An electroencephalogram may aid 
in differentiating seizure from syncope, and if obtained during a provocative 
test, may permit recognition of hysterical "fainting spells. " 

Syncope, for the most part, is a benign and transitory condition. How- 
ever, it nnay occasionally indicate the presence of a serious organic disorder. 
For this reason, repetitive syncopal episodes should alert the physician and 
lead to a careful and systematic search for such underlying disease. 

References 



25. Bicfeerstaff, E. P... Basilar Artery Migraine. Lancet /.IS-l? (Jan. 7) 1961. 
Bickerstaff, E. R.; Impairment of Consciousness in Migraine I^ncel 
1961. 

Selby, G., and Lance, J. W.: Observations on 500 Cases of Migra 
Headache. J, Neurol., Neilrosurg. & Psychiat. 2J.-23-32 (Feb.) 19(>0. 



26, Biclerstaff, E. H.: Impairment of Consciousness in Migraine. lancet 2 1057-1059 (Nov U) 
1961. ' - I 

27. Selby G., and Lance, J. W.: Observations on 500 Cases of Migraine and Allied Vascular 



* * * * 



Medical News Letter, Vol. 43, No. 3 15 

SUBMARINE MEDICINE SECTION 




BASIC PHYSIOLOGY IH SCUBA. AMD SKIH DIVIKG* 

Karl E. Schaefer, M.D., Headj Physiology Branch, Medical Research 
Laboratory, U. S. N. Sutraarine Base, New London, Connecticut 

Pulmonary Gas Exchange 
During Breathhold Dives 

During the training of submarine crews in sutanarine escape procedures, 
such as "free or buoyant ascent," instructors at the escape training tank fre- 
quently hold their breath under water and perform "skin" dives to depths as 
great as 90 feet. The ascent is carried out by climbing up a line. These div- 
ing maneuvers are similar to those practiced by sponge and pearl divers . The 
escape training tank at the New London Submarine Base afforded us an opportu- 
nity to study the pulmonary gas exchange during this type of diving. 

Prior to the descent the diver exhaled to residual volume and then inhaled 
h liters from a spirometer. After reaching a predetermined stopping point dur- 
ing diving, he exhaled the major part of his expiratory volume through a mouth- 
piece into the first bag used for the collection of mixed expired airj he ex- 
haled the remainder into a second bag used to collect "alveolar air." (The 
latter us^lally contained 10 to 20 percent of the total expiratory volume.) The 
bags were brought to the surface. Gas samples from the bags were collected 
and analyzed and the volumes measured. The CO^ and content in the lungs at 
various depths was calculated f ran .the measurea ^s tensions and volvmies of 
mixed expired and alveolar air, and the total dry gas pressure in the lungs. 

Due to the increase in pressure the CO- tension in the lungs rose quickly 
above the venous C0_ tension and a reversed CO gradient developed. At 90 
feet approximately 50 percent of the pre~dive CO content of the lungs had 
disappeared jand wa-s taken up by the blood and tissues. The influx of carbon 
dioxide into the lungs during ascent appeared to be rather slow and it was 
foiand possible to control the alveolar CO^ level by the speed of ascent. If 
the ascent was fast the alveolar CO tension attained on reaching the surface 
was low, between 30 Se 35 ram. Hg; if^the ascent was slow^ the alveolar COg ten- 
sion rose to l)-0-45 m)a. Hg. The alveolar oxygen tension rose from control 
levels of 100 mm. Hg to 300 mm. Hg at 90 feet depth and fell on ascent rapidly 
during the last 10 feet to such low values as 25-30 rm. Hg. 

The disappearance of COp from the lungs during dives together with the 
oxygen utilization and mechanical ccanpression of the thorax as the subject de- 
scends produce a progressive shrinkage of the total chest voltime. These fac- 
tors may explain the observation reported by Behnke that subjects holding 
their breath under water increase in weight and are less buoyant. 

Reprinted from Connecticut Medicine , June I963, Vol. 27, No. 6, p. 308. 



16 Medical News Letter, Vol. 43, No. 3 

It is reassuring to knov that a diver at 90 feet is somewhat protected in- 
asmuch as the CO tension does not rise to dangerous levels and the oxygen ten- 
sion is rather high. Under these conditions, "breath -holding time is consider- 
ably prolonged. However, during the last part of ascent or just at the moment 
the diver reaches the surface, available oxygen may become so depleted as to 
produce anoxia. The alveolar oxygen falls to a very low level at the end of 
ascent from dives to 90 feet. We sav one instructor becoming confused in the 
manent he gave the alveolar sample after reaching the surface, but he quickly 
recovered after the first breath. His alveolar concentration vas 3.5 per 
cent (pO alv. 28 mm. Hg^) . With a very low oxygen content and a normal or be- 
low normal C0„ concentration, the nitrogen content of the alveolar air at the 
end of the dive is markedly increased, 89 per cent compared with a nonnal 79 

per cent. 

Measurements of blood gases, lactic acid, respiration and metabolism made 
on four subjects before and after diving to 90 feet produced the following re- 
sults: The CO content of blood rose very slightly while the oxygen content 
fell during thi dive. The lactic acid content in the blood increased about 5- 
fold during the dive. In this case a sample was taken one minute after the 
dive. The lactic acid decreased to a level slightly above normal within five 
minutes. On more frequently collected venous samples, peak lactic acid con- 
centrations were also measured after three minutes of recovery following the 
dive. The one minute values were consistently lower than the three minute 
values. This corresponds with findings recently obtained by Scholander in 
pearl divers. The delayed but large rise in lactic acid foimd during the re- 
covery phase in man is quite similar to that observed in the seal and might 
according to Scholander also be interpreted as an indication of reduced muscle 
blood flow during the dive. 

Respiration was increased 3-fold during the first minute after the dive 
and returned to normal level within 15 minutes. The excess oxygen uptake 
above the control level after the dive was limited to four minutes and aver- 
aged lifOO cc. in four subjects. This indicates that the oxygen debt taken 
during the dive of I-I/2 minutes is in the order of lUOO cc. The excess CO^ 
exhalation within the first four minutes after diving averaged 900 cc . 

Scholander also noted a marked diving bradycardia during active diving. 
The pulse rate was reduced to one-half of the pre-dive value, while breath- 
holding at the surface leads to a much smaller decrease in pulse rate. Extra 
systoles were noted in ECG tracings during the dive and arrhythmias and atrial 
fibrillation during the recovery phase. Blood pressure measurements made 
after breathholdlng under water and in air did not show significant changes in 
systolic and diastolic pressures . 

Adaptation To Diving 

The breathholdlng time of tank instructors was found to be 105 seconds, 
while that of a group of laboratory personnel was 60 seconds. The vital ca- 
pacity of 16 tank instructors was not only significantly larger than that of 
the group of 16 laboratory personnel, but it was also 20 per cent higher than 
could be predicted by their height, weight, and age, using the West formula. 
Total lung capacity, tidal volvuae, vital capacity and respiratory reserve were 
markedly Increased in the tank instructor group as compared with the labora- 
tory personnel. To decide whether the lung volumes really change during the 
course of duty at the tank, a longitudinal study was carried out and the lung 
volumes of tank instructors measured at the beginning of their tour of duty 
and after one year. Respiratory reserve, tidal volume, vital capacity, and 



Medical News Letter, Vol. 43, No. 3 17 

total capacity shoved a significant increase while residual capacity decreased. 
The maximum average depth a diver can reach without getting a thoracic squeeze 
depends on the ratio of total Ixing capacity to residual capacity and the vol- 
vime of the airways. The observed change in this ratio results in a 20-30 foot 
extension in the inaximum safe depth after one year of duty. 

The ventilatory response to increased concentration of CO^ and to a lower- 
ed concentration of (IO.5 per cent) was found significantly decreased in 
instructors at the esiape training tank as compared with the laboratory per- 
sonnel. The CO- tolerance curves were obtained by exposing subjects for 15 
minutes to 3.3, 5.^ and T.5 per cent CO . Alveolar ventilation and alveolar 
gas CO tensions were determined at the end of the exposure period. The stim- 
ulus response curves (or tolerance curves) to CO showed, in the case of the 
tank instructors, a shift to the right and a decreased slope. The high toler- 
ance to CO is developed during the diving period and lost after a three-month 
lay-off period as shown in COp sensitivity tests in eight tank instructors. 

Blood gas and electrolyte changes observed at the end of a longer period 
of water work were similar to those noted during adaptation to prolonged ex- 
posure to CO . They consisted in a decrease in pH, increase in pCO and bi- 
carbonate levels commensurate with an increase in hematocrit and rea cell 
cation exchange, e.g., increase in red cell sodium and decrease in red cell 
potass i\am. These adaptive changes disappeared after a three -month layoff 
period. Furthermore, evidence of an increase in COp stores, as the result of 
diving, was obtained in instructors following a two-year period of water work 
when compared with data obtained after a three-month layoff period. During 
constant hyperventilation, lasting for one hour, more CO^ was eliminated and 
the end tidal CO tension was significantly elevated under the first condition. 
The decreased sensitivity to CO eind low found in skin divers represents an 
adaptation similar to that observed in diving animals. The changes in lung 
volumes, consisting of an increase in total lung capacity, vital capacity and 
tidal volume, and decrease in residixal volume, might contribute to the re- 
duced sensitivity to C0_ because of the relationship fovnd between large tidal 
volume, small respiratory rate and low response to CO . 

Physiological Problems and Hazards Associated 
With Various Diving and Escape Procedures 

Since the clinical problems of diving are discvissed by Dr. Bond and air 
embolism by Dr. Liebow, I only want to mention the physiological problems as- 
sociated with the hazards of diving. 

All divers, whether skin, SCUBA, or deep sea, are subject to the effects 
of vinequalized pressure differences across the air-containing structures, mid- 
dle ears, sinuses, lungs, and gastro-intestinal tract (barotrauma). The skin 
diver is safe from air embolism but might develop a thoracic squeeze with pul- 
monary edema and hemorrhage if he descends to a depth at which the total air 
in the limg is ccanpressed to a volume smaller than the residual air. To avoid 
this danger, skin diving should be limited to a 50-foot depth. The SCUBA 
diver, who can stay under water for a considerable time, is exposed to the 
same hazards as the conventional diver using heljnet and suit: decompression 
sickness, air embolism, oxygen toxicity and nitrogen narcosis. 

Submarine Escape (Free and Buoyant Ascent) 

Buoyant ascent (aided by an inflated life Jacket) has been successfully 
carried out from a depth of 3OO feet, at an ascent rate of 3H0 feet/minute, 
without respiratory distress. Recent evaluation of alveolar gas exchange data, 
obtained during buoyant ascent from 90 feet has shown that alveolar COg 



18 Medical News Letter, Vol. 43, No. 3 

tension can be kept at normal levels at the average ascent rates used. 
SCUBA Diving 

Several cases of unexplained loss of consciousness occurred vith the use 
of oxygen (closed circuit) diving equipment in vhich canisters are employed 
for CO removal. CO intoxication vas implicated as the most likely cause of 
the "sfea-llow water blackout." Using open or closed circuit Self Contained 
Under Water Breathing Apparatus (SCUBA) units at a greater depth, the direct 
effect of pressure produces an increased density of the breathing mixture, re- 
sulting in an increased breathing resistance. Under these conditions, the 
work of breathing was found increased in both the breathing apparatus and in 
the airways of the diver. Pulmonary resistance at four atmospheres pressure 
Increased twofold compared with the values at sea level. Froeb compared the 
respiratory responses to CO in l6 professional divers using SCUBA equipment 
with those of nondivers and did not find any evidence of adaptation to CO- in 
the SCUBA divers. In studies of well-trained and less trained under-water 
swimaers of the U. S. Kavy Underwater Demolition Team, using a closed circuit 
oxygen breathing unit, a higher mean end tidal pCOp tension was found in the 
trained swimmers during swims at a speed of 1.1 to l8 km/hr. 'While resting 
xmder water, differences in end tidal pCO were negligible. 

Deep Sea Diving 

In deep sea diving ("Hard Hat Diving"), in which the conventional suit 
and helmet are used, a large amount of air has to be ventilated to prevent an 
accumulation of GO^ and often this is not fully accomplished. Moreover, at 
greater depths, breathing resistance becomes very marked and may easily lead 
to CO retention. Lanphier found that a considerable number of experienced 
deep lea divers at the U.S.N. Experimental Diving Unit showed CO retention 
dviring iMder water work. The respiratory minute volume declined during work 
dives to moderate depth using oxygen-nitrogen mixtures. The degree of reten- 
tion of carbon dioxide was 3related to the ventilatory response to CO^. When 
breathing resistance was reduced by the use of helium-oxygen mixtures, the 
C0„ retention was small or absent. 

A more detailed account of the physiological problems involved in diving 
has been given elsewhere. 

Summary 

Studies of pulmonary gas exchange during breathhold dives to 90 feet dem- 
onstrated the existence of a reversed CO- gradient frcaa the lungs into the 
blood during descent at the 50 foot depth. The influx of CO into the lungs 
during ascent is regulated by the speed of ascent. 

Extremely low alveolar tensions between 25-35 mm. Eg, found after sur- 
facing from 90-foot dives, emphasize the existing danger of hypoxia. On the 
basis of these findings it is recommended that skindives should be limited to 
a 50-foot depth. Observations on metabolic changes during diving and diving 
bradycardia are discussed. 

Adaptation to skin diving consists in: l) increase in total lung capacr 
Ity and decrease in residual voltane — resulting in an extension of the safe 
maximum depth; 2) increased tolerance to high C0_ and low . 

Hazards associated with various diving and escape procedures are 
discussed. 



The 2U refferenees and 2 figures in this paper have been deleted. 



Medical News Letter, Vol. 43, No. 3 19 

FROM THE NOTE BOOK 

First Cruise Reenlistment 

A review of hospital corpsmen reenlistment statistics for fiscal year 1964 
is disappointing, especially those for first craise personnel. The problem 
of retaining qualified and trained non-rated personnel is serious. It is 
imperative that all commands review their reenlistment programs carefully. 
Pursuit of a vigorous campaign periodically is not the answer. Efforts must 
be continuous with a specific goal of improvement in the First Cruise 
Reenlistment rate. 

The stability of enlisted personnel desired by our activities, monetary 
savings, trained future petty officers — all result from concerted efforts in 
reenlisting worthwhile men. Are incentive programs understood by officer 
and senior enlisted personnel responsible for providing career guidance and 
counseling? Are these programs fully explained to all eligible personnel? 
Are reenlistment interviews, established as basic requirements in BUPERS 
Instruction 1133,3E, being conducted? The answers to these questions may 
reveal leadership deficiencies and suggest to the command possible solutions. 
Accomplishment of an effective reenlistment program must be inspired by a 
desire of senior personnel to enthusiastically and publicly support a vocation 
they have elected — a Navy career. 

The references listed below are published to recall attention to avail- 
able reenlistment and career incentives: 

BUPERS Instruction 1133.3 (current series) 
Subj: Reenlistnnent Program 

BUPERS Instruction 1133. 13 (current series) 

Subj: Selective Training and Retention (STAR) Program 

BUPERS Instruction 1306. 73 (current series) 
Subj; Duty Assignment Options as Reenlistment Incentive; 

promulgation of 

BUPERS Instruction 1430. 14 (current series) 

Subj: Autom^atic Advancement to Pay Grade E-4 for Certain 

Class "A" School Graduates 

Enlisted Transfer Manual, NAVPERS 15909, Chapter 12.8 
Assignment to School as a Reenlistment Incentive 

BUMED Instruction 1510. 12 (current series) 
Subj: Career Incentives Available for Group X(Medical) 
and Group XI (Dental) Ratings 

— Hospital Corps Division, BuMed 



20 Medical News Letter, Vol. 43, No. 3 

The Naval Historical Foundation 

Founded in 1926, the Naval Historical Foundation is one of the most dedicated 
and respected historical Foundations. Its membership includes persons in all 
walks of life, military and civilian. In pursuit of its mission of preserving 
all that is finest in naval tradition for the generations to come, the Foundation 
operates the Truxtun-Decatur Naval Museum located at 1610 H Street, N. W. , 
in our nation's capital. Here one can see items from the Foundation's col- 
lections that reflect the heritage of our great naval service. From time to 
time, exhibits are changed to depict various periods or special events in 
American history. The current series of exhibits covers the Navy's role in 
the Civil War. 

Many documents shown by the Foundation are on long term loan from 
the Library of Congress where they are available to scholars and researchers. 
The Foundation is recognized as having the largest available collection of doc- 
'uments and manuscripts on the U. S. Navy. Other projects include an educa- 
tional historical film, lectures, and publication of items of historical interest. 

As is true in any organization of this type, funds are obtained through 
annual membership dues and contributions. At this time, funds are much 
needed by the Foundation to assist in the inventory and cataloging of its vast 
collections. Further information regarding the Foundation and its member- 
ship may be obtained by writing to the Naval Historical Foundation, c/o Navy 
Department, Washington 25, D. C. 



Navy Nurses' Program in Anesthesia 

The Navy's Bureau of Medicine and Surgery has announced that its Program 
in Anesthesia for Nurse Corps Officers was granted full accreditation by the 
American Association of Nurse Anesthetists in December 1963. 

In September 1962, eleven Navy Nurses were admitted to the first class 
in Anesthesia for Nurse Corps Officers. In order for this program to be effec- 
tive, it was necessary to meet the requirements of the AANA. Having met the 
minimum requirements, students will take a national examination in May '64 
to qualify as certified registered nurse anesthetists. 

One year of didactic work is given at George Washington University 
and the National Naval Medical Center. The second year of clinical experience 
in Anesthesia is provided at one of four selected Naval Hospitals where stu- 
dents work under constant supervision. Classroom instruction exceeds the 
required 250 hours; 500 hours of clinical instruction are available to students 
in the selected Naval Hospitals. 

In August 1963, a committee froin National Headquarters of the AANA 
visited the Naval Medical School, NNMC. Course content and lesson plans 
were scrutinized, students interviewed, and a lecture attended by members 
of the inspection team; clinical areas were inspected. Applications are being 
accepted from members of the Navy Nurse Corps for the third class. 

— Nursing Division, BuMed 



Medical News Letter, Vol. 43, No. 3 21 

Navy Ntirse Corps Senior Officer Assignments 

CDR Florence E. Alwyn NC USN (B S, University of California, San 
Francisco), Chief Nurse, Headquarters Support Activity, Saigon, 
South Viet-Nam has been reassigned to USNH Bremerton as Chief of 
Nursing Service. 

CDR Veronica M. Bulshefski NC USN (Hospital of the University of 
Pennsylvania, Philadelphia; B SN E, Indiana University, Bloomington; 
MS, Management, U.S. Naval Postgraduate School, Monterey, Calif.), 
Chief Nurse, USNH Pensacola has been reassigned to USNH Oakland 
as Chief of Nursing Service. 

CDR Lorraine M. Hankey NC USN (St. Barnabas School of Nursing, 
Minneapolis; B S, University of Washington, Seattle), Chief Nurse 
USNH Bremerton has been assigned to USNH Pensacola as Chief 
of Nursing Service. 

CDR Grace E. Jacobs NC USN (Springfield Hospital, Springfield, 
Mass. ; B S, Boston University), Chief Nurse, USNH Quantico, Va. , 
has been reassigned to USNH Chelsea as Chief of Nursing Service. 

— Nursing Division, BuMed 



Radioactivity - A New Publication . National Bureau of Standards Handbook 86; 
November 29, 1963, 53 pages; 40^. (Order from Superintendent of Documents, 
U.S. Government Printing Office, Washington, D. C. 20402.) 

Handbook 86 is the latest in a new series of publications presenting 
the 1962 recommendations of the International Commission on Radiological 
Units and Measurements (ICRU); the new series will eventually contain six 
reports. This Handbook deals with radioactivity and presents recommenda- 
tions of the Commission agreed upon at its meeting in Montreau, Switzerland 
in April 1962. It contains: (1) direct and relative measurements of the activity 
of radioactive sources, (2) low-level radioactivity in materials and its rela- 
tion to radiological measurements, (3) availability of radioactive standards, 
and (4) technics for measuring radioactivity in samples and living subjects. 

Erratum Notice Re: Salary and Rank of Naval Interns . The information 
contained on page 39 of Vol. 43, No. 1, 3 January 1964 issue of the Navy 
Medical News Letter was partially in error. Paragraph #5 under Naval 
Internships (Continued) is corrected to read: 

"#5. Under present Navy Promotion policies, naval interns are initially 
appointed in the rank of Lieutenant. Interns with dependents receive 
approximately $8,375 per year; those without dependents receive 
approximately $8,074 per year. " — Medical Corps Branch, ProfDiv, BuMed 



2Z Medical News Letter, Vol. 43, No. 3 




DEIMTAL I f^m^i IS SECTION 



The Physician, the Patient, and S tatistics 

Ernest L.. Wynder MD, New York, Division of Preventive Medicine, Sloan- 
Kettering Institute for Cancer Research. JADA 186(13): 1150. 

Man's apparent lack of concern for factors that contribute to disease presents 
an important challenge to those dedicated to the prevention of disease and the 
maintenance of health. Both the physician and the patient are faced with this 
challenge. 

Individual clinical or laboratory findings have a relative risk value of 
incurring a given disease. Those findings with a high risk value may still be 
relatively small for an individual patient over a short period of time. The dif- 
ficulty in overcoming this lack of concern is compounded when the finding is 
asymptomatic. It is at this stage that preventive nneasures may be effective 
whereas, once symptoms are observable the disease may be difficult or im- 
possible to cure. 

Dr. Wynder uses myocardial infarction as a disease to illustrate the 
difficulty discussed. As a paraphrase in the field of dentistry, periodontal 
disease is presented. Of the factors contributing to periodontal disease these 
are listed: calculus, malocclusion, diet, lack of massage, poor oral hygiene, 
habits, and general physical condition. All of these factors have a relative 
bearing on the course of the disease but statistically none can be assigned a 
rating of 100%. Consequently, how many dentists undertake measures to re- 
duce or eliminate among their patients all of those factors amenable to change? 
More often than not, patients will return a year later with no clinical symptom 
present. Consequently, the dentist feels that he acted wisely. However, for 
the few individuals who do have the asymptomatic clinical finding and subse- 
quently develop the pathology, the dentist must learn not to think in terms of 
the risk for an individual over a limited period, but in terms of the risk ap- 
plied to a population for a long time. Simiilar reasoning must be followed when 
examining a patient. Thus all available diagnostic aids should be used in exam- 
ining all tissues. 

To continue the paraphrase in another part of Dr. Wynder' s paper: The 
dentist who is aware of statistical chance in the terms just discussed needs to 
be further trained in the proper method of communication with his patients so 
that he can express in clear and comprehensible terms what must be done and 
what may be expected if the advice is not followed. Only to the extent that this 
can be accomplished can the dentist effectively practice preventive dentistry. 



Medical News Letter, Vol. 43, No. 3 23 

This concept of therapeutic preventive dentistry may be neglected even by 
dentists specializing in preventive dentistry. 

A. great challenge faces all practitioners of preventive medicine and 
dentistry. They must educate their colleagues and the public -at-large in the 
meaning, interpretation, and application of statistical risk to an individual 
patient. In the execution of this task lies the very root, if not indeed the whole, 
of preventive medicine and dentistry. Its full appreciation has a significant 
influence on the maintenance of health and the preservation of life, 

:{5 ?[? ?J; sj; tjc ijc 

Pathogenesis of Bacterial Endocarditis* 

Alfred A. Angrist and Masamichi Oka. JAMA 183: 249-252, January 26, 
1963. From Dental Abstracts 8(12): 719-720, December 1963. 

Acute bacterial endocarditis is associated with sepsis and more severe illness 
and greater stress, in contrast to a subacute bacterial form of the disease with 
the usual picture of chronic indolent illness. 

Based on the authors' observations of heart valves at autopsy and of 
experimental data, the following concept of endocarditis is offered. Prolonged 
stress leads to changes in the valve, at least in some instances. Nonbacterial 
vegetations become the focus for localization of bacteria. Such contamination 
from the blood stream with the common alpha hemolytic streptococci would 
be expected in fleeting and passive instances of bacteremia, such as those 
that follow a tooth extraction or sinus puncture. In instances of sepsis, more 
virulent microorganisms usually are associated with an active bacteremia. 
Instances of sepsis are more apt to affect healthy as well as damaged valves; 
then the interstitial lesion in the valve, the overlying nonbacterial thrombotic 
endocarditis, and its contamination occur in rapid sequence and merge to be- 
come part of the general clinical picture of sepsis. Each form of bacterial 
endocarditis contributes its particular features to yield the final characteristic 
pathologic picture and clinical course. 

Dental Sepsis and Lung Infection* 

Fallon, Martin and Main, David G. Ashludie Hospital, Dundee, Scotland. 
Dental Practitioner 13: 281-283, March 1963. From Dental Abstracts 8 
(12): 722, December 1963. 

Dental inspection of a series of 165 patients with pneumonitis (excluding carci- 
noma, bronchiectasis, and specific infections) revealed that gross dental sepsis 
was the cause of the lung infection in 51 patients (30%). Nine (25%) of 35 lung 
abscesses were attributed to dental sepsis. 



24 Medical News Letter, Vol. 43, No. 3 

In most patients the dental sepsis manifested itself as periodontal 
disease, with or without caries. In 38 of these patients, the sepsis was so 
gross that all teeth had to be extracted. In 10 patients the sepsis was limited 
and was dealt with by selective extraction and scaling. 

In the 51 patients with lung infection and dental sepsis, there was no 
source of infection other than that of dental origin. The recoveries which 
followed dental treatment suggested dental sepsis as the only causative factor. 
In most of the 51 patients, infection occurred in the typical aspiration sites 
in the lung; that is, the posterior segment of the upper lobes and the apical 
segment of the lower lobes. 

:J: sf: sjc sj: !}: ^ 

Review of Research 
on Initiation of Periodontal Disease* 

B. Cohen, Royal College of Surgeons, London, England, International 
Dental Journal 13: 70-79, March 1963. From Dental Abstracts 8(12): 739- 
740, December 1963. 

Theories that periodontal disease originates from a systemic source no longer 
command the support they once enjoyed. In the past 5 years of periodontal 
research under review, several investigations have lent support to the view, 
now widely accepted, that systemic factors, although capable of modifying the 
reaction of damaged periodontal tissues, cannot reasonably be held to account 
for the onset of the syndrome. The determining factors in periodontal disease 
are local in origin and can be aggravated by systemic factors; the predisposing 
factors are often systemic in origin and act by altering the normal metabolic 
activities of tissues or by inhibiting their normal reparative capacity (Carranza 
and Carranza, 1959). 

The importance of bacteria in the initiation of periodontal disease has 
attracted wide attention in recent years. Whether or not the existence of peri- 
odontal disease in germ -free mice is accepted, there can be no denying that 
the disease is modified and doubtlessly aggravated by oral organisms gaining 
access to the periodontal tissues once pocket formation has commenced. The 
possible importance of Bacterioides melaninogenicus in this respect is sug- 
gested by Macdonald (I960). 

The World Health Organization Expert Committee (1961) concluded that 
bacterial plaque is a factor of paramount importance in periodontal disease. 
Rough surfaces in contact with the gingiva are injurious because they contribute 
to plaque retention rather than for any mechanical irritation they may inflict. 

No one has been able to demonstrate an initial invasion by bacteria of 
the intact periodontium, but Cohen (1959) suggested that a path of ingress for 
the toxic products of surface organisms may be established in the course of 
tooth eruption. Permeability to bacteria also has been ascribed to the lytic 
effects of certain bacterial metabolites on epithelial cells and to the persistence 
of vestigial (enamel) epithelium after tooth eruption. 



* These articles are copyrighted by the American Dental Association. Reprinted 
by permission. 



Medical News Letter, Vol. 43, No. 3 25 

Personnel and Professional Notes 

Leadership in Action . The traditional responsibility for promulgating to the 
crew internal information which will insure that every man knows what the 
situation is now, what probably may happen in the future, and what is expected 
of him relative to each, rests with the Division Officer. The Division Officer 
concept of personnel management is an old and tested way of accomplishing 
assigned tasks with optimum efficiency and satisfaction. 

At the Naval Dental Clinic, Norfolk, Virginia, the Division Officer con- 
cept has been adapted to the principle of personal leadership. This new plan 
is a departure from the common practice of assigning the Division Officer's 
responsibility to the Medical Service Corps Officer or to the Warrant Officer 
on board who, with the scope of his administrative duties, does not have the 
time to do a thorough job as Division Officer. In this successful new leader- 
ship plan, the enlisted personnel are organized in "Divisions" of not more than 
12 technicians. Each Division is assigned a junior dental officer as Division 
Officer. This officer is responsible for continuing personal contact with each 
man in his Division. To facilitate this personal touch, the Division Officer main- 
tains a notebook containing all pertinent details on each man, such as family 
size and problems, educational background, ambition, interests, hobbies, 
disciplinary history, etc. The limited size of each Division facilitates the Di- 
vision Officer's personal contact with each man, at no interference with the 
officer's primary duties. This personal recognition supports a sense of be- 
longing in each technician. It stimulates his motivation. 

In a leadership organization of this type, the command, the Division 
Officers and the men realize benefits. The command gains improved efficiency, 
effectiveness, and morale. Each Division Officer gains experience in the best 
principles of leadership. Each man gains the dignity and satisfaction of personal 
recognition-intangible but real factors which stimulate his motivation and,thereby 
improve his chances for advancement. The principle of this leadership plan is 
that a person's motivation is stronger when his talents are recognized, when 
he is encouraged to make full use of his talents, and when his good performance 
is recognized. This is a positive program which avoids many common pitfalls, 
e.g. , a person's frustration when misplaced, when his talents are wasted or 
when recognition centers on his mistakes rather his accomplishments. The 
Division Officer concept of personnel management discussed here is worthy 
of trial. 

AFIP Hosts Postgraduate Course . The Armed Forces Institute of Pathology 
will host the annual postgraduate course in "Pathology of the Oral Regions, " 
to be held March 2 through March 6, 1964. The course will be directed by 
CAPT Henry H. Scofield DC USN, Chief of the Dental and Oral Pathology Di- 
vision, and is designed to provide dentists, physicians and trainees in oral 
and general pathology a fundamental knowledge of various aspects of oral dis- 
ease. It will be presented by specialists in the fields of oral and general pa- 
thology, oral surgery, periodontics and caries and cancer research. Develop- 
mental disturbances of the head, neck and oral region, inflammatory diseases 



26 Medical News Letter, Vol. 43, No. 3 

of the oral mucosa and jaws, the oral manifestations of certain systemic dis- 
eases and neoplasms of the oral cavity and related structures will be discussed 
in detail and their clinical, roentgenographic and microscopic characteristics 
will be illustrated. Special attention will be directed to current trends in caries 
research, the role of exfoliative cytology in cancer detection and recent de- 
velopments in cancer investigation. Lectures will be correlated with case 
presentations, microscopic seminars and round table discussions. 

Leadership Discussion Material. The attention of all dental personnel is di- 
rected to SUPERS NOTICE 1910 of 26 December 1963, concerning the gravity 
of receiving a less than honorable discharge. The message contained therein 
is poignant material for leadership discussion. 

New Schedule for Naval Examining Board . Effective February 1964, the Naval 
Examining Board will act continuously on applications for regular Navy as they 
are received in the Dental Division, Bureau of Medicine and Surgery. This is 
a change from previous practice wherein the Board previously met only semi- 
annually, in February and August. Candidates may expect to be notified of 
acceptance or rejection, between four and six weeks after the application has 
been received by the Dental Division, BUMED. 

Navy Dental Corps Presentations at Boston Dental Society . CAPT G. W. Ferguson 
DC USN, Dental Officer at the U. S, Naval Station, Newport, Rhode Island, 
presented a talk entitled "Educational and Research Opportunities and Ac- 
complishments of the U.S. Navy Dental Corps" before the North Metropolitan 
District Dental Society in October 1963 in Boston, Mass. CAPT Howard W. 
Pierce DC USN, presented a paper covering the subject, "Crown and Bridge 
Cast Coping Technics. " The First Naval District Dental Officer, CAPT W. A. 
Goldring DC USN, was the program chairman. 

CAPT Eastman Clinician at Dental Society Meeting . CAPT Arthur D. Eastman 
DC USN, the Dental Officer at U. S. Naval Air Station, Whidbey Island, Oak 
Harbor, Washington was the clinician at the October nionthly meeting of the 
Mount Baker District Dental Society. 

Navy Dental Officers Hold New Posts . During recent weeks, the Navy Dental 
Corps has achieved four measures of recognition by their civilian fellow den- 
tists. RADM Frank M. Kyes DC USN, was elected Vice President of the ADA. 
CAPT Angus W. Grant DC USN was elected Vice President of the American 
Academy of Oral Roentgenology. CAPT Victor J. Niiranen DC USN, was elected 
Vice President of the American Academy of Maxillo -facial Prosthetics. CDR 
Loren V. Hickey DC USN, was appointed Chairman of the Rubber Dam Com- 
mittee of the American Academy of Gold Foil Operators. He is also a member 
of the Literature and Publicity Committees of that organization. 

3}: ^ i'f sle sit >[c 



Medical News Letter, Vol. 43, No. 3 27 




OCCUPATIONAL MEDICINE 



Chennical Health Hazards and Their Control* 

Abstracts from Quarterly Occupational Health Reports. 

Chlorine. During routine service of a swimming pool chlorinator system, two 
civil service employees were assigned the task of disconnecting the used chlo- 
rine cylinder and replacing it with a new one. The valve on the old cylinder 
was apparently corroded and was difficult to turn; as a result the cylinder was 
disconnected from the system before complete closure of the valve was accom- 
plished. The man nearest the discharge end of the cylinder was splashed with 
liquid chlorine which emerged under pressure from the incompletely shut-off 
valve. By the time the valve was completely closed, the man suffered a degree 
of exposure which produced typical symptoms of chlorine inhalation. He was 
brought to the dispensary where he was given supportive treatment and was 
then transferred to the naval hospital where he remained under intensive care 
for two days. He was then symptom free and was discharged to full duty. The 
other man had much leas exposure and did not require hospitalization. 

In this incident the men failed to carry out the routine precautions re- 
quired when servicing chlorinator systems. Canister masks which offer pro- 
tection against atmospheres containing 2% chlorine were available at the work 
site. These masks should be worn when piping connections of the chlorine sys- 
tems are to be opened. The wearing of these nnasks is mandatory when mech- 
anical difficulties are experienced during work on the chlorinators. (Naval Air 
Station, Alameda, Calif. ) 

Sewage Tank Cleaning Procedure; Shipboard. Shipyard personnel were con- 
cerned over the health hazards involved when scraping and wire brushing the 
interior of a tank aboard a MSTS ship. Investigation revealed that the tank is 
used to collect sewage and waste fron^ sanitary facilities aboard ship before 
the waste material is pumped overboard. The men were concerned whether 
disease -producing conditions would be present when the work was done. At 
the time of the visit the tank was being cleaned by an outside contractor. The 
cleaning was done by recirculating a caustic solution through the tank and then 
rinsing with fresh water. The solution used contained three quarters of a 
pound of caustic soda per gallon and a small amount of detergent. This solu- 
tion was used at 189°F. for about one hour. Assurance was given to personnel 



28 Medical News Letter, Vol. 43, No. 3 

that no living disease-producer present from the sewage would remain after 
the above treatment. Precautionary measures were recommended to avoid 
any health hazard from possible caustic residue which might be dispersed as 
a dust during the descaling operation. These measures included air-supplied 
respirators, protective gloves and protective skin creams for exposed skin 
areas. (Naval Shipyard, New York, N. Y. ) 

Coal Tar Emulsion Dust, Eye Irritation. An employee reported to the dispen- 
sary for treatment of irritation of the eyes. It was learned that he was clean- 
ing surfaces in a tank on a floating crane, prior to the spray painting. It was 
also learned that the existing dried coating was of the coal tar emulsion type. 
The irritancy of fresh coatings of the latter as well as its light sensitization 
reaction on skin and raucous membranes are well known. It is now apparent 
that this coating retains such irritant properties even after long periods of 
drying. To prevent further reactions, it was recommended that eye-cup or 
monogoggles be used for this work. (Naval Shipyard, Charleston, S. C. ) 

Fiberglass Sandblasting. Within the space of a few days, a number of employ- 
ees from various shops and trades reported to the dispensary with complaints 
of severe itching on various pa»rts of the body. Investigation revealed a com- 
mon space aboard ship in which each employee had worked. It was further 
learned that sandblasting of old coating in this space was recently completed. 
It was further learned that plastic sheets, composed of laminated fiberglas im- 
pregnated with epoxy resins covered the surfaces of the subject ship space. 
The sandblasting had created a mixture of the frit and very small particles of 
fiberglass. The effect of the sandblasting appeared to change the physical con- 
dition of the fiberglass to a highly irritating fuzz. It was recommended that 
any person entering this space be supplied with coveralls which have been care- 
fully taped at the wrists and ankles. (Naval Shipyard, Charleston, S. C. ) 

Cold Temperatures; Non-Fogging Safety Glasses. Environmental tests of pro- 
pellants require vibration while stored at extreme temperatures. These may 
range from a high of 140°F. (desert) to a low of minus 65 F. (arctic). The 
operators of the environmental chamber are required to enter the chamber to 
make adjustments and measurements at these extreme temperatures. Arctic 
type clothing is used when working in the chambers at the low temperatures. 
However, safety glasses required for eye protection cause difficulties due to 
fogging. It has been fovuid that a plastic cover goggle intended to fit over pre- 
scription glasses does not fog when worn over standard safety glasses. The 
M-9 gas mask has also been found to be relatively free of fogging troubles, 
even when passing from ambient temperatures of over 100 F. directly into 
the test chamber at minus 65°F. (Naval Ordnance Test Station, China Lake, 
Calif. ) 



* Submitted by Naval Shore Activities. 



Medical News Letter, Vol. 43, No. 3 29 

Detecti on of Nonorganic Hearing Loss 

Report of Working Group 36. Critical Evaluation of Methods of Testing and 
Measurement of Nonorganic Hearing Impairment. NAS-NRC Committee on 
Hearing, Bioacoustics, and Biomechanics, 1963. Pages 7 - 11, November 1963. 
A skillful examiner can often detect a nonorganic hearing impairment during 
the taking of history and physical examination. Further evidence may be gained 
from routine audiometric tests with pure tones and speech. If nonorganic im- 
pairment is suspected, a variety of specialized tests may be administered. 
The determination of the amount of nonorganic hearing loss is difficult and es- 
timates having reasonable accuracy can be made only under favorable conditions. 
Few quantitative tests are available. 

It is rarely possible to distinguish between subconscious, psychogenic hear- 
ing loss and outright malingering. Positive proof of voluntary simulation can 
be obtained only by inducing the tested person into a frank admission of deceit. 
Several of the specialized tests may be helpful in encouraging admission of 
malingering. Because of the difficulty in discriminating between psychogenic 
hearing loss and malingering, the following classification and evaluation of 
tests refer to nonorganic hearing loss without regard to its origin. Tests that 
appear particularly useful for detecting outright malingering are pointed out. 
It should be emphasized that none of the available teats is capable of dem- 
onstrating absence of nonorganic involvement. They are conclusive only when 
their outcome is positive. 

Procedures for the detection of nonorganic hearing loss may be divided into 
three broad categories: informal observation, indicator tests, and proof tests . 
The first two categories overlap with routine auditory examination; the third 
category aims specifically at the nonorganic hearing loss. 

. Informal observation. An alert examiner can usually detect the nonorganic 
origin of hearing loss by noting obvious discrepancies between auditory be- 
havior and test performance. He should observe the patient carefully during 
the interview and when taking the case history. The attitude of the patient 
toward his hearing loss can be revealing. The person with a severe organic 
hearing loss is usually demonstrably worried about it, the person with a non- 
organic hearing loss often seems quite unconcerned. Establishment of a suit- 
able motivation is also important. Few, if any, individuals malinger without 
a motive. Frequently, when the motive is removed, the nonorganic component 
of hearing loss disappears. 

Indicator tests. Several teats in this category belong to routine audiometric 
examination, i. e. , determination of hearing loss for pure tones and speech 
(Speech Reception Threshold). They rely on the consistency of the listener's 
responses to test signals. The inexperienced listener with nonorganic hearing 
loss has difficulty in duplicating his responses on repeated trials, particularly 
when speech is the test signal. If on repeated trials hearing loss varies by 
more than 10 decibels (dB), nonorganic hearing loss should be auspected. The 
chief limitation of this method is that the expert malingerer can duplicate his 
responses by noting a loudness level well above his threshold and waiting until 



30 



Medical News Lietter, Vol, 43, No. 3 



this level is reached before responding. 

Instead of comparing results of repeated trials, the Speech Reception 
Threshold (SRT) can be compared to the average hearing loss at 500, 1000, 
and 2000 cycles per second (cps). In organic hearing loss, both agree to with- 
in a few decibels. If the difference exceeds 10 dB, nonorganic hearing loss 
should be suspected. Under these conditions the measured hearing loss for 
pure tones is usually higher than for speech, since control of responses by 
judging loudness ia more difficult for speech than for pure tones. 

In general, the indicator tests rely on the listeners' conscious decisions 
with respect to the audibility of test stimuli presented in quiet, i. e. , without 
any interfering sound. Responses involving conscious decisions are known to 
depend highly on the motivation of the listener. - For instance, if the listener's 
job depends on acute hearing, he will tend to make some responses in the ab- 
sence of any stimulus. If, on the contrary, he receives compensation for 
hearing loss, he may tend to respond only when the presence of the stimulus 
becomes very obvious. It is assumed that individuals with normal hearing or 
with organic hearing loss are highly motivated to respond to test signals. On 
this basis intra-test variabilities and inter-test relationships are established. 
Significant deviations from the expected results indicate a nonorganic impair- 
ment. While it is inconceivable that any one individual could master the stim- 
ulus-response relationships to a point of being able to conceal the nonorganic 
origin of his hearing loss if given a sufficiently extensive battery of uncom- 
plicated psychophysical tests, no one test of this category can be considered 
sufficiently conclusive for a definitive diagnosis. 

Proof tests . Proof tests are specifically oriented toward detecting nonor- 
ganic hearing loss although some of them may also be used for other purposes. 
They are usually more complex and more time-consuming than the indicator 
tests. They should not be administered unless informal observation or at 
least one of the indicator tests, or both, have led to a suspicion of nonorganic 
hearing loss. The proof tests can be divided into five subcategories, depend- 
ing on the basic nnethod involved. 

Stimulus interference. It is possible to include in the first category all 
tests that rely on patients' voluntary responses, but where the test stimulus 
is presented together with an interfering stimulus. The basic principle in- 
volved is the observation that one sound cannot appreciably interfere with 
the audibility of another sound unless it itself is audible. When the interfer- 
ing soimd becomes effective before it reaches the previously indicated threi 
hold of audibility, it suggests that the threshold has been elevated by nono: 
ganic hearing loss. 

When a test of this kind is so designed that the test sound is completely 
masked out before the interfering sound reaches the threshold indicated by 
the patient, the test results may provide convincing evidence of nonorganic 
loss. This is so because the listener loses all information necessary to make 
decisions correlated with changes in the test sound. The Stenger Test ful- 
fills these requirements. It is based on the principle that a relatively loud 
sound in one ear makes an identical but fainter sound inaudible in the other 



!S. 



Medical News Letter, Vol. 43, No. 3 31 

ear. The Stenger Test can produce a quantitative estimate of the nonorganic 
component of hearing loss. It is probably the most fool proof test against 
malingering requiring only a two-channel pure-tone or speech audiometer. 
Unfortunately, its usefulness is limited to strongly asymmetrical hearing 

losses. 

Another test that is based on stimulus interference, although of quite a 
different nature, is the Swinging Voice Test. In this test, a story is delivered 
to the listener through earphones in such a way that parts of it reach both ear- 
phones; other parts are channelled alternately to each earphone separately. 
The listener is requested to repeat the story, and his answer depends on wheth- 
er he heard the story through both or through only one earphone. Like the 
Stenger, the usefulness of the Swinging Voice Test is limited to asymmetrical 
hearing losses. Otherwise, it is highly efficient and requires only a two- 
channel speech audiometer with an appropriate switch. 

When the interfering sound does not make the test stimulus completely in- 
audible but only changes some of its characteristics, a sophisticated listener 
may obtain sufficient information to conceal the nonorganic origin of his hear- 
ing loss. Nevertheless, where such a situation exists, experience with the 
Doerfler-Stewart Test, has shown that the concealment is extremely difficult. 
In this test, a saw-tooth noise is made to interfere with speech reception. 
The signal-to-noise ratio at which speech reception is affected by noise has 
been determined for listeners with normal hearing and for those with organic 
hearing loss. Test results that deviate appreciably from the established norma 
strongly indicate nonorganic hearing loss. 

The great advantage of the Doerfler-Stewart Test is that it applies to bin- 
aural hearing losses. It requires only a small modification of standard speech 
audiometers and is not difficult to perform. When skillfully administered, it 
can be of help in uncovering malingering, and it can produce a quantitative 
estimate of the nonorganic component. 

Auditory motor control. In tests of this subcategory, the listener makes 
motor responses that are influenced by or are dependent on the auditory feed- 
back. Speaking or reading out loud are typical examples. If the individual 
can actually hear the sound he produces, and uses auditory clues, his perform- 
ance can be altered by interference with the auditory feedback. Conversely, 
a change in performance due to interference with the feedback indicates that 
the individual can hear the sound. The Lombard Test and the Delayed Feed - 
back Test are typical examples. 

In the Lombard Test the tested person is given a text to read out loud. An 
interfering noise is produced by means of earphones or a loudspeaker, and its 
intensity is gradually increased. When the noise becomes sufficiently strong 
to interfere with speech perception, the reader tends to raise his voice. The 
Lombard Test can be administered monaurally or binaurally and requires only 
a noise source. Its major shortcoming is a strong susceptibility to learning 
certain cues, allowing the patient to set a voice level sufficiently invariant so 
that repetition decreases its efficiency. 

The Delayed Feedback Test, known also as Delayed Playback or Delayed 



3Z Medical News Letter, Vol. 43, No. 3 

Side Tone Test, is based on a time delay between the patient's speech output 
and his auditory feedback. When the delayed input is sufficiently strong and 
is audible to the listener, his speech tends to become loud and distorted. The 
test has shown considerable promise and is difficult to outmaneuver when done 
properly. However, it requires special equipment, and there are some indi- 
viduals on whom the delayed feedback has little effect. In cases of moderate 
organic loss with nonorganic overlay the test is of limited value because it 
requires excessively high signal levels. 

Eeflex responses. In tests of this category, the function of the auditory 
system is inferred from reflex responses, like eyeblink or change of skin re- 
sistance. Since the listener is not asked to make conscious decisions, the 
psychological factors responsible for nonorganic hearing loss are presumably 
eliminated, and the reflex threshold may be taken as an indication of normal 
hearing or organic hearing loss. It should be kept in mind, however, that a 
reflex response to a sound stimulus can only be taken as evidence that the 
peripheral end organ and associated neural structures of the brain stem are 
functioning. It does not necessarily indicate that the sounds that elicit reflex 
response are also consciously perceived. Reflex responses to sovind stinauli 
have to be conditioned, for instance by a mild electric shock, and several dif- 
ficulties arise from the conditioning procedure. It is not always possible to 
elicit the desired reflex even when the stimulus is known to be above the thres- 
hold of audibility. A response that is established for strong stimuli may vanish 
at lower sound intensity levels that are still above the threshold. During pro- 
longed testing, habituation may abolish the reflex but not necessarily if a 
periodic reinforcement is used rather than a regular schedule. In addition, 
the use of aversive conditioning stimuli, especially of electric shock, has cer- 
tain negative psychological effects. 

The most widely used test of this category is based on reflexive changes 
of skin resistance. It is known under the names: Electrodermal Response 
(EDR) , or Psychogalvanic Skin Response (PGSR). The conditioned reflex to 
tone bursts is elicited by pairing the tones with electric shocks. When the 
test administrator is experienced and skillful, conditioned responses can usu- 
ally be maintained during fairly long test sessions. The temporal pattern of 
resistance changes is plotted by means of a graphic level recorder. Because 
of spontaneous skin responses, and because the reflex is not always elicited 
by the same sound signal on repeated presentations, evaluation of the record- 
ings is sometimes difficult. The test requires special equipment and skilled 
personnel. Under favorable conditions, it can produce quantitative data and 
serve effectively in detecting nonorganic hearing loss. 

The Eyeblink Reflex has not been used routinely because it disappears at 
near threshold stimulus intensities and is subject to fast habituation. 

Electroencephalography. Tests of this category rely on changes in the 
Electroencephalogram (EEG) that may be produced by sound stimuli. The 
technique is severely limited by the requirement of elaborate equipment and 
by the fact that with current methods of recording no specific change in the 
wave form of the EEG is seen to follow a sound signal. Noticeable changes 



Medical News Letter, Vol. 43, No. 3 33 

occur in whatever wave form is present at the time of auditory stimulation, 
but they decrease rapidly as the signal approaches threshold intensity aa de- 
termined by ordinary audiometer tests, and disappear before the threshold is 
reached. There is some evidence that low level outputs from the cortex can 
be detected by computers which average EEG responses evoked by sound stim- 
uli. Further experiments must be done before the procedure can be used in 
clinical tests. In any event, the broad use of the technique is limited by the 
relatively high cost of the necessary computer equipment. 

Narcosis and hypnosis. The use of narcosis or hypnosis in examining 
patients with suspected nonorganic hearing loss is successful only in the hands 
of an experienced psychiatrist, and, even then, to a limited degree. These 
methods are best employed on individuals who have suffered from shock that 
resulted in a sudden hearing loss. They serve little or no purpose after the 
hearing loss has lasted for several years. In general, narcosis and hypnosis 
do not yield as valid or as precise information as do audiological techniques, 
but this technique has not been systematically investigated. 

Although a large number of tests for nonorganic hearing loss are available, 
no test is foolproof. Quantification of nonorganic hearing loss and differentia- 
tion between voluntary malingering and subconscious psychogenic, auditory 
disorders appear particularly difficult. In each case of suspected nonorganic 
hearing loss, several methods must be used to substantiate the diagnosis. It 
is recommended that, after informal examination, one or several indicator 
tests and at least one proof test be administered. 

:(!)}! sf: sis :^ 

Laser -Medical and Industrial Hygiene Controls 



H.E. TebrockMD, * New York, N. Y. , W.N. Young MD, ** Bayside, 
N. Y. and W. Machle MD, *** Miami, Fla. , Journal of Occupational 
Medicine, 5 (12); 564-567, December 1963. 

Lasers are devices that produce highly parallel, intense beams of light of a 
single wave length by stimulated emission from various materials. This new 
technologic development has fired the imagination of research laboratories in 
the whole scientific community. Research is being performed to use lasers 
in space communications systems, optical radars and tracking systems, and 
perhaps even as radiation instruments and weapons. From a communications 
standpoint they may be used to transmit an extremely large amount of informa- 
tion on many different channels in a vacuum, fiber optic system, or pipe. 



* Dr. Tebrock is Medical Director, Sylvania Electric Products Company, 
** Dr. Young is Medical Director, General Telephone and Electronics Lab- 
oratories, Inc., *** Dr. Machle is Professor of Industrial Medicine, Uni- 
versity of Miami (Fla. ) presented at the XIV International Congress on 
Occupational Health, Sept. 16, 1963, Madrid, Spain. 



34 Medical News Letter, Vol. 43, No. 3 

Maiman, in I960, utilized a ruby rod, the ends of which were polished, 
optically flat, and parallel. One end of the rod was silvered, the other partial- 
ly silvered. This ruby consists of . 05% chromium oxide in the aluminum oxide 
crystal. Around this ruby rod, a xenon pumping light excites a number of the 
chromium atoms to rise to an excited or metastable state. From this higher 
energy state, the chromium ions drop spontaneously to a lower energy level, 
each discharging a photon. It is reflected back and forth between the silvered 
ends of the ruby, and then out from the partially silvered end. This photon 
emerges at a wave length of 6943 Angstrom \inits. Many new materials have 
been discovered which made excellent lasers, including gases such as helium 
and neon, liquids such as europium chelate in alcohol, and semiconductors 
such as gallium arsenide for junction lasers. The gas lasers are designed to 
produce continuous -output beams at many different wave lengths at relatively 
lower output power than the ruby and neodymium solid-state lasers. Gallium 
arsenide is intermediate in power output. 

From a health or occupational environmental control view point, pro- 
blems exist in three different areas; those of (1) the much higher powered, 
pulsed, solid-state lasers; (2) the lower powered, continuous -wave gas laser; 
and (3) junction diode lasers. 

SOLID-STATE LASERS. First, we shall consider the solid-state pulsed 
laser. If it is the ruby type, the emission will be at 6943 A, and its greatest 
hazard will be to the retina of the eye. Light incident to the cornea of the eye 
is focused by cornea and lens to a small point on the retina, causing a resultant 
concentration many orders of magnitude greater than light incumbent upon the 
cornea. The lesion produced is probably due to heat, but it appears to differ 
in many ways from the effect of the typical xenon-powered Zeiss photocoagula- 
tors. Because xenon is a high ultraviolet and infrared source it has similar 
heat qualities, but perhaps the monochromatic laser may also possess ioniza- 
tion or other hazards. However, although both produce an energy effect on 
the retina similar to an ordinary coagulation or burn of the retina, there have 
been observations that the pigment is deposited much more quickly in a laser 
coagulation than in a xenon coagulation (sometimes within 48 hr. ). It appears 
that the principal factor in laser energy absorption by living tissue is pigmen- 
tation. Areas of darker pigmentation absorb more light (laser energy) than 
do areas of lesser pigmentation. Taking advantage of this greater affinity of 
laser energy for greater pigmented areas, McGuff experimentally utilized 
laser radiation on human melanomas transplanted onto guinea pig cheek pouches. 

Experimental burns of the rabbit retina have been produced by Zaret 
in chinchilla gray rabbits, as well as in animals with a more deeply pigmented 
retina. There is a tremendous difference in lesion size and severity, with 
deeper pigmentation producing the greater severity of reaction. Some hemor- 
rhage occurs from the very center of the chorioretinal burn, but it is generally 
limited in area and quite small in diameter. Another unusual effect is the 
sharp, punched- out lesion produced by the laser on the retina. Utilizing a 
pulsed ruby laser with an output of 0. 1 J/sq. cm. in. 0005 sec. , with a pupil 



Medical News Letter, Vol. 43, No. 3 35 

diameter of 8 mm. , a nodal retinal point of 10 mm. , and 95% transmissibility 
of the ocular media, the dose to the retina is 270 J/sq. cm. in . 0005 sec. The 
dose reduced by a factor of 10 still produced a visible lesion, whereas after 
reduction by a factor of 100 it did not. Therefore, an approximate threshold 
value for the gray rabbit lies between 6. 45 and 0. 65 cal. /sq. cm. 

Campbell has used the laser as a retinal coagulator in retinal tears and 
detachments in the human. He used an apparatus in which ruby-lased light, 
aimed with a binocular ophthalmoscope, is reflected through a dichroic mirror 
directly into the eye. Many coagulations were made with this device in human 
subjects and at present, in Campbell's hands, it has supplemented the Zeiss 
photocoagulator in the treatment of human retinal tears. Many fvmdus photo- 
graphs have been taken illustrating simultaneous xenonarc retinal lesion and 
laser lesion (done at the same time in the same eye). Although the methods 
seem equally effective in producing retinal "welding, " many differences are 
noted in the time appearance of pigment and the nature of the lesion. 

Grosoff has made some threshold determinations of eye injury due to 
ruby energy. Since a rabbit is 3 diopters farsighted, the investigator assumes 
a 2/10-mm. lesion size on the retina, a 21/2% loss at the cornea due to reflec- 
tivity, a 97% transmission through the ocular media, and 22% retinal absorp- 
tion. Using steam as the visible threshold of injury, Grosoff fo\md (in the 
Belgian hare and chinchilla gray rabbit) 2-14 J/sq. cm. to be the threshold 
dose. A median figure for all eyes examined resulted in 9 J/sq. cm. as the 
threshold at the retina. On the other hand, with neodymium lasing at 10, 600 A, 
2 1/2 times more power is necessary since only 9% of the energy is absorbed 
by the retina pigment epithelium. Therefore, 47 J/sq. cm. is the threshold 
dose at the retina with neodymium. 

Ham found that 0. 5 cal. at 1 msec, produced a lesion. In 1 sec. , 3 
cal. /sq. cm. were needed to produce a lesion, while at . 0001 sec. , between 
0. 1 and 0. 2 cal. produced a lesion. He found an average pigment -epithelium 
absorption of 43%, with a range of 7%-62%; and, also, that ruby had a much 
higher transmission through the ocular media than neodymium. Solon, on the 
other hand, feels that . 01 cal. /sq. cm. might be damaging to the retina. The 
low-power laser does not appear to damage the skin or other structures of 
the body in any way unless focused. However, when focused, it would produce 

burns. 

Q switching, Q spoiling, or other high-power ruby and neodymium 
devices will produce damage to the skin and allied structures with an unfocused 
beam. The output of these devices is in the range of 100 J or greater. This 
is achieved by interposing a shutter between the Q cavity and the partially 
silvered end. A xenon flash lamp is then fired and finally the shutter is opened, 
allowing one giant but very short pulse out of the partially silvered end. This 
may be further amplified by passing through another Q cavity of an unsilvered 
laser system. The lesion produced by the unfocused beam on the skin of the 
exposed individual appears to be a first-or second-degree burn of varying se- 
verity, depending on the amoxmt of pigment epithelium in the skin. Because 
of the parallel nature of the rays it will be sharply circumscribed and quite 



36 Medical News Letter, Vol. 43, No, 3 

shallow in depth. Microscopic sections of such a lesion show bizarre niitotic 
figures, which raises the question of carcinoma in situ. 

GAS LASERS . The helium -neon gas laser works on a principle slightly differ- 
ent frona that of the solid-state lasers. The helium atoms are carried to an 
excited state by a radio-frequency discharge through the gas-filled tube. Neon 
atoms initially in the ground state are excited to a nnetastable state of helium 
atoms in an excited state. A mirror at one end and a partial mirror at the 
other end reflect photons back and forth until a discharge occurs through the 
partially silvered end. The resultant emission of most of these devices is at 
6328 A, and, of course, is continuous wave rather than pulsed. Power outputs 
so far have been in the mw range with . 01 w the average output. From this, 
one could plot that . 01 w incident to the cornea would give a retinal dose of 
4.1 w. /sq. cm. in a well-lighted room. In a 1-sec. period, this would be 4.1 
J/sq. cm. retinal dose or about half the threshold indicated by Grosoff. 

GALLIUM ARSENIDE JUNCTION LASER . Another form of laser which has 
recently become continuous -wave type is a gallium arsenide junction laser. 
This consists of a gallium arsenide diode with positive and negative regions. 
In the plane dividing these two regions, photons are emitted by electrons of 
the negative region, migrating and dropping into holes in the positive region. 
This emission is aroiond 9000 A at room temperature but drops to 8400 A at 
lower temperatures; hence, it may be rather easily tuned. At present the 
energy output is in the range of 0.1 w/amp. , sufficient to produce a threshold 
lesion inasmuch, as the energy calculated at the retina is 1330 w. /sq. cm. in 
a well-lighted room. In a 1-sec. period, this would be equivalent to 1330 J/sq. 
cm. , well above the threshold. 

SAFE OPERATING LIMITS. The authors' recommendations for control are 
based on the specific laser energy involved. In the case of the pulsed solid- 
state laser of modest power {10 J or less), eye shielding is necessary to keep 
the retina dose below 9 J/sq. cm. , provided that the time factor of the pulse 
remains at or around . 0005 sec. If the time factor reaches the . 00001-sec. 
range, a lower allowance at the retina is recommended to allow for the lesser 
opportunity for heat loss. At the present tenmilliwatt output of the helium - 
neon gas laser, it does not appear to be a hazard. However, much more work 
must be done before this is verified. The junction laser, on the other hand, 
must have attenuation of its beam before entering the eye. This can be ac- 
complished by an antilaser eye shield. High-powered lasers (100 J plus) should 
not be directed at human skin or other system because of the unknown nature 
of possible deleterious effects. 

Control is really based on one simple cardinal rule -avoidance of the 
principal beam and its reflection. This can be achieved primarily by fixing 
the beam on an optical bench, avoiding all reflections of the beam by an ap- 
propriately planned diffuse environment. Where the apparatus is portable or 



Medical News Letter, Vol. 43, No. 3 37 

there is a specific attempt to aim at or detect an observer, protection must 
be provided for the observer. This can be in the form of protective antilaser 
lenses for the eyes, and clothing over the skin. This antilaser eye shield, at 
present, must match the wave length of the laser being operated. 

For 6943 A (ruby laser), the Bausch & Lomb antilaser eye shield 
6000-7000 gives adequate protection for power levels up to 100 J per burst. 
Obviously, one must not depend upon the glasses alone for protection, but 
must still follow the cardinal rule of avoidance of the principal beam. Filter 
glass (E.G. 18), has also been effective as an antilaser eye shield at this wave 
length. However, the dichroic filter added in the Bausch & Lomb preparation 
make it preferable, in the writers' estimation. In the 10, 600-A range, Bausch 
& LiOmb has a No. 3 welding glass and dichroic filter which give adequate 
protection. Of great importance is excellent room lighting in order to keep 
the pupil of the eye as constricted as possible, thereby decreasing the amount 
of energy impinging on the retina. Along these same lines, the degree of 
focus or fixation of the eye upon the laser source is also important. If the 
eye is accommodated for distance the dose of the energy source at the retina 
will be higher than if accommodated to objects of reference in the room at 
about the same distance as the laser source. 

All skin burns should be carefully followed by regular exanninations, 
because of the iinusual microscopic findings found on tissue section after ap- 
plication of the 100-J-per-burst pulse ruby laser. Aside from increasing 
experimental knowledge, we do not feel excision or biopsy to be warranted. 

With respect to persons who may work as engineers or technicians in 
a laser program, funduscopic photographs should be taken and carefully re- 
viewed to rule out applicants having gross lesions that inight later appear to 
be possible laser burns or complications. In addition, a complete ophthal- 
nnological examination {including slit-lamp examination) should be carried 
out-particularly if the laser will function at wave lengths of 10, 600 A or longer. 
Repeated examinations -at reasonable intervals depending on expo sure -should 
be made, checking any retinal lesions, lenticular opacities, and skin burns. 
It is also essential to hold spot checks, particularly to uncover changes in the 
practices of protection. 

The principles of controlling environmental laser hazard are as fol- 
lows : 

1. Avoidance of principal beam and its reflection 

2. Proper education of personnel involved 

3. General information given those who might be casually exposed 

4. Use of warning devices to indicate laser in operation 

5. Policing and clearing of area for long-range operation 

6. Use of proper antilaser eye shields on any observer likely to be exposed 

7. Use of covmt-downs, with persons closing eyes or looking away from 

pulsed, high-power beam 

8. Reporting of all persistent after-images to medical department 

9. Funduscopic and slit-lamp examination of all people involved in laser 
operations 



38 Medical News Letter, Vol. 43, No. 3 

Laser research may well lead to beams of longer and longer wave length as 
new materials are discovered that satisfy laser requirements. There is also 
a simultaneous effort to secure increased power output. Since new effects may 
be noted as the equipment changes, new or additional health and safety require- 
ments must necessarily be formulated to meet the ever changing experiments, 

>;« ^ ^it sj: ;{: 




RESERVE ^Sm^ SECTION 



Meeting of the American Mosquito 
Control Association 

The annual meeting of the American Mosquito Control Association will be held 
in Chicago, 111. , 1 to 4 March 1964. A Military Section in conjunction with this 
meeting will be held on the 1, 2, 3, and 4 March 1964. The Bureau of Medicine 
and Surgery has been advised that the Military Section will be sponsored, su- 
pervised, and conducted by the ^Department of the Army; each session will be 
at least two hours in duration. 

By authority of the Chief of Naval Personnel, one retirement point may 
be credited to eligible Naval Reserve Medical Department officers in attend- 
ance at each session. 

?JC 'r* 'Tt* T? T^ 

ATTENTION: Reserve Nurse Corps Officers on inactive duty 

This is an excellent time for you to return to active duty if you are qualified 
and interested. We have vacancies due to normal attrition and increasing 
numbers for voluntary retirements. If you hold the rank of Lieutenant Junior 
Grade or Lieutenant and could complete 20 years of active duty before reach- 
ing age 55, you may apply. Application for recall to active duty NavPers 2929 
maybe obtained at the nearest naval recruiting station. 

Sectional Meetings, ACS 

A Sectional Meeting of the American College of Surgeons will be held in Den- 
ver, Colo. , 17 to 19 February 1964. A Military Section in conJTinction with 
this meeting will be held on the 17, 18, and 19 of February 1964. The Bureau 
of Medicine and Surgery has been advised that the Military Section will be 



Medical News Letter, Vol. 43, No. 3 39 

sponsored, supervised, and conducted by the Department of the Navy; each 
session will be at least two hours in duration. 

By authority of the Chief of Naval Personnel, one retirement point may 
be credited to eligible Naval Reserve Medical Department officers in attend- 
ance at each session. 

The Sectional Meeting of the American College of Surgeons will be held in New 
Orleans, La. , 16 to 19 March 1964, A Military Section in conjunction with this 
meeting will be held on.l6, 17, 18, and 19 March. The Bureau of Medicine and 
Surgery has been advised that the Military Section will be sponsored, super- 
vised, and conducted by the Surgeon General, Department of the Navy; each 
session will be at least two hours in duration. 

By authority of the Chief of Naval Personnel, one retirement point may 
be credited to eligible Naval Reserve Medical Department officers in attendance 
at each session. 

^ ^ :^ -^ :i: 

Navy Ensign 1915 Medical Program 
(continued) 

QUESTIONS AND ANSWERS 

1. Since participation in the Senior Medical Student Program is considered 
active duty, will it count as a year for retirement? 

Yes, under either the appropriate regular or reserve retirement law. 

2. If the 4 years in medical school count for longevity when on active duty, 
will a Navy intern be in an over 4-year pay grade? 

Yes, and in addition, the 4 years in medical school will count as years 
of satisfactory Federal service providing the student earns at least 50 
retirement points per year. He may do so by active participation in the 
vacation training programs; i. e. , research cind clinical clerkship train- 
ing. 

3. What are the reasons for rejecting applications from Ensign 1915 officers 
for the Senior Medical Student Program? 

All applications are carefully reviewed by boards both in the Bureau of 
Naval Personnel and the Bureau of Medicine and Surgery for the purpose 
of determining the best qualified students. Since candidates for the Sen- 
ior Medical Student Program must qualify for a commission in the regular 
Navy, qualifications are therefore more severely considered. Some ap- 
plicants are rejected because of physical disabilities, others are rejected 



40 



Medical News Letter, Vol. 43, No. 3 



because of low academic records and reports which indicate that the individu- 
al is not otherwise best suited for military service. 

4. What are the chances of being assigned sea duty during the 2 or 3 years 
obligated service? 

At the present time the chances are that 1 out of every 6 individuals serv- 
ing during their 2 or 3 years obligated service are assigned aboard ships 
at sea. Tours of sea duty range from 12 to 24 months. 

5. On completion of internship, may a request for a desired duty station be 
made? 

Yes. An opportunity is afforded to indicate 4 types of duty desired. These 
preferences will be considered in the ultimate assignment of duty station. 

(To be continued) 

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